diff --git a/R/cobb_douglas.R b/R/cobb_douglas.R
index c3a8a6d50592361a9b3ebce76e1be9655832bc51..501e95b4b2c2e9da7c40105090895a3d515e974d 100644
--- a/R/cobb_douglas.R
+++ b/R/cobb_douglas.R
@@ -8,5 +8,7 @@
 #'   \item{l}{dbl Labor input}
 #'   \item{q}{dbl Output}
 #' }
-#' @source \url{http://sourceforge.net/projects/gretl/files/datafiles/POE4data.tar.gz/download)}
+#' @source Hill, Griffiths and Lim: ``Principles of Econometrics (4e)``
+#'
+#' \url{http://sourceforge.net/projects/gretl/files/datafiles/POE4data.tar.gz/download}
 "cobb_douglas" # Name Ihres Datensatzes
diff --git a/R/eduinc.R b/R/eduinc.R
index e1596efb30a80777b8f4ee8cfd566fcca212801b..8a718f16a4bdde184d39db0ce7ac179c3f1b2417 100644
--- a/R/eduinc.R
+++ b/R/eduinc.R
@@ -11,5 +11,9 @@
 #'   \item{xtra_x5}{dbl An artifically generated variable used to illustrate the effect of irrelevant variables.}
 #'   \item{xtra_x6}{dbl A second artifically generated variable used to illustrate the effect of irrelevant variables.}
 #' }
-#' @source{Mroz, T. A. (1987). The Sensitivity of an Empirical Model of Married Women`s Hours of Work to Economic and Statistical Assumptions. Econometrica, 55(4), 765-799.} \url{http://sourceforge.net/projects/gretl/files/datafiles/POE4data.tar.gz/download}
+#' @source Hill, Griffiths and Lim: ``Principles of Econometrics (4e)``
+#'
+#' Mroz data: Mroz, T. A. (1987). The Sensitivity of an Empirical Model of Married Women`s Hours of Work to Economic and Statistical Assumptions. Econometrica, 55(4), 765-799.
+#'
+#' \url{http://sourceforge.net/projects/gretl/files/datafiles/POE4data.tar.gz/download}
 "eduinc" # Name Ihres Datensatzes
diff --git a/R/food.R b/R/food.R
index 478a69e4cb4b50cc3f313c5f9e6b090d5a399f3d..76a1dba7af3d1ce26efa2ce23ef42d0cfe6f7d90 100644
--- a/R/food.R
+++ b/R/food.R
@@ -1,12 +1,14 @@
-#' Kurze Beschreibung des Datensatzes (hier eigene Beschreibung ergaenzen)
+#' Food expenditures vs. income cross-section data
 #'
-#' Etwas laengere Beschreibung des Datensatzes (hier eigene Besachreibung ergaenzen)
+#' A data set that relates food expenditure to income taken from Hill, Griffiths and Lim: Principles of Econometrics (4e)
 #'
 #' @format A tibble with 40 rows and 3 variables:
 #' \describe{
-#'   \item{X}{dbl ?}
-#'   \item{food_exp}{dbl ?}
-#'   \item{income}{dbl ?}
+#'   \item{X}{dbl A variable that denominates the respective observation}
+#'   \item{food_exp}{dbl Weekly food expenditure in $}
+#'   \item{income}{dbl Weekly income in $100}
 #' }
-#' @source \url{Quellangabe (hier beispielsweise als Link)}
+#' @source Hill, Griffiths and Lim: ``Principles of Econometrics (4e)``
+#'
+#' \url{http://sourceforge.net/projects/gretl/files/datafiles/POE4data.tar.gz/download}
 "food" # Name Ihres Datensatzes
diff --git a/R/gfc.R b/R/gfc.R
index b3268f94ac0e2e43871a0c2a2f0d7ceba5218527..50b6779200764c17fc789876e0ac851234acd9b3 100644
--- a/R/gfc.R
+++ b/R/gfc.R
@@ -1,12 +1,16 @@
-#' Kurze Beschreibung des Datensatzes (hier eigene Beschreibung ergaenzen)
+#' Gross domestic products for Europe and United States of America (time-series data)
 #'
-#' Etwas laengere Beschreibung des Datensatzes (hier eigene Besachreibung ergaenzen)
+#' 60 quarterly observations (1995q1 - 2009q4) of GDP for Europe and USA. Standardized so that the value of GDP is equal to 100 in 2000.
 #'
 #' @format A tibble with 60 rows and 3 variables:
 #' \describe{
-#'   \item{quarter}{chr Angabe des Beobachtungszeitpunkts: Quartalsweise Beobachtung (4 pro Jahr) zwischen dem ersten Quartal 1995 und dem letzten Quartal 2009}
-#'   \item{GDPE}{dbl ?}
-#'   \item{GDPU}{dbl ?}
+#'   \item{quarter}{chr Indication of observation date: Quarterly observation (4 per year) between the first quarter of 1995 and the last quarter of 2009.}
+#'   \item{GDPE}{dbl Gross domestic product for the Euro Area standardized so that the value of GDP is equal to 100 in 2000.}
+#'   \item{GDPU}{dbl Gross domestic product for the United States standardized so that the value of GDP is equal to 100 in 2000.}
 #' }
-#' @source \url{Quellangabe (hier beispielsweise als Link)}
+#' @source Hill, Griffiths and Lim: ``Principles of Econometrics (4e)``
+#'
+#' Original data: Statistical Bulletin, Reserve Bank of Australia
+#'
+#' \url{http://sourceforge.net/projects/gretl/files/datafiles/POE4data.tar.gz/download}
 "gfc" # Name Ihres Datensatzes
diff --git a/R/phillips.R b/R/phillips.R
index e9a52442a2a5518244622721eab746e3ce8e7b0b..47b841645a005b4557b3b69d37b8c3f49910f136 100644
--- a/R/phillips.R
+++ b/R/phillips.R
@@ -1,12 +1,16 @@
-#' Kurze Beschreibung des Datensatzes (hier eigene Beschreibung ergaenzen)
+#' Phillips cureve data for Australia (time-series data)
 #'
-#' Etwas laengere Beschreibung des Datensatzes (hier eigene Besachreibung ergaenzen)
+#' Quarterly (1987Q1 - 2009Q3) time-series data for Australian Phillips curve.
 #'
 #' @format A tibble with 91 rows and 3 variables:
 #' \describe{
-#'   \item{obs}{chr ?}
-#'   \item{inf}{dbl ?}
-#'   \item{u}{dbl ?}
+#'   \item{obs}{chr Indication of observation date: Quarterly observation (4 per year) between the first quarter of 1987 and the third quarter of 2009.}
+#'   \item{inf}{dbl Australian Inflation Rate (Percentage Change in the Consumer Price Index with an adjustment for 2000Q3 when a national sales tax was introduced)}
+#'   \item{u}{dbl Australian Unemployment Rate (Seasonally adjusted)}
 #' }
-#' @source \url{Quellangabe (hier beispielsweise als Link)}
+#' @source Hill, Griffiths and Lim: ``Principles of Econometrics (4e)``
+#'
+#' Reserve Bank of Australia
+#'
+#' \url{http://sourceforge.net/projects/gretl/files/datafiles/POE4data.tar.gz/download}
 "phillips" # Name Ihres Datensatzes
diff --git a/R/qtm.R b/R/qtm.R
index 9a6c5baac89cd25b229b4ee1ce7c4f797a7a2d0c..51ac0ab9ff325bb5cdb9a8fea92c4e30d3061cd5 100644
--- a/R/qtm.R
+++ b/R/qtm.R
@@ -1,12 +1,16 @@
-#' Kurze Beschreibung des Datensatzes (hier eigene Beschreibung ergaenzen)
+#' Quantity of money and price level (time-series data)
 #'
-#' Etwas laengere Beschreibung des Datensatzes (hier eigene Besachreibung ergaenzen)
+#' Data to analyze the relationship between the quantity of money (as M3) in the economy and the aggregate price level (GDP deflator).
 #'
 #' @format A tibble with 180 rows and 3 variables:
 #' \describe{
-#'   \item{obs}{chr ?}
-#'   \item{m}{dbl ?}
-#'   \item{p}{dbl ?}
+#'   \item{obs}{chr Indication of observation date: Quarterly observation (4 per year) between the first quarter of 1961 and the last quarter of 2005.}
+#'   \item{m}{dbl Percentage change in M3 (a measure of the quantity of money)}
+#'   \item{p}{dbl Percentage change in the GDP deflator (a measure of aggregate price)}
 #' }
-#' @source \url{Quellangabe (hier beispielsweise als Link)}
+#' @source Hill, Griffiths and Lim: ``Principles of Econometrics (4e)``
+#'
+#' International Financial Statistics, International Monetary Fund
+#'
+#' \url{http://sourceforge.net/projects/gretl/files/datafiles/POE4data.tar.gz/download}
 "qtm" # Name Ihres Datensatzes
diff --git a/man/cobb_douglas.Rd b/man/cobb_douglas.Rd
index 0b8f1da518e17dc965f590235c7164d77ac31b4c..ffc3c91b84ea636ae76f4b0353e11b0955370633 100644
--- a/man/cobb_douglas.Rd
+++ b/man/cobb_douglas.Rd
@@ -13,7 +13,9 @@ A tibble with 33 rows and 3 variables:
 }
 }
 \source{
-\url{http://sourceforge.net/projects/gretl/files/datafiles/POE4data.tar.gz/download)}
+Hill, Griffiths and Lim: \verb{Principles of Econometrics (4e)}
+
+\url{http://sourceforge.net/projects/gretl/files/datafiles/POE4data.tar.gz/download}
 }
 \usage{
 cobb_douglas
diff --git a/man/eduinc.Rd b/man/eduinc.Rd
index 613aa55a7a962a6d363ea22e43a52adb38ff720c..4342afba54879d72e23e90d8cc0091c3036aa7dc 100644
--- a/man/eduinc.Rd
+++ b/man/eduinc.Rd
@@ -16,7 +16,11 @@ A tibble with 428 rows and 6 variables:
 }
 }
 \source{
-{Mroz, T. A. (1987). The Sensitivity of an Empirical Model of Married Women`s Hours of Work to Economic and Statistical Assumptions. Econometrica, 55(4), 765-799.} \url{http://sourceforge.net/projects/gretl/files/datafiles/POE4data.tar.gz/download}
+Hill, Griffiths and Lim: \verb{Principles of Econometrics (4e)}
+
+Mroz data: Mroz, T. A. (1987). The Sensitivity of an Empirical Model of Married Women`s Hours of Work to Economic and Statistical Assumptions. Econometrica, 55(4), 765-799.
+
+\url{http://sourceforge.net/projects/gretl/files/datafiles/POE4data.tar.gz/download}
 }
 \usage{
 eduinc
diff --git a/man/food.Rd b/man/food.Rd
index 84a96efbca28ad3b88e6aa5118fbfceb8a63b438..6eec1d0a9517f67f0949d35196b5f44889359ef1 100644
--- a/man/food.Rd
+++ b/man/food.Rd
@@ -3,22 +3,24 @@
 \docType{data}
 \name{food}
 \alias{food}
-\title{Kurze Beschreibung des Datensatzes (hier eigene Beschreibung ergaenzen)}
+\title{Food expenditures vs. income cross-section data}
 \format{
 A tibble with 40 rows and 3 variables:
 \describe{
-\item{X}{dbl ?}
-\item{food_exp}{dbl ?}
-\item{income}{dbl ?}
+\item{X}{dbl A variable that denominates the respective observation}
+\item{food_exp}{dbl Weekly food expenditure in $}
+\item{income}{dbl Weekly income in $100}
 }
 }
 \source{
-\url{Quellangabe (hier beispielsweise als Link)}
+Hill, Griffiths and Lim: \verb{Principles of Econometrics (4e)}
+
+\url{http://sourceforge.net/projects/gretl/files/datafiles/POE4data.tar.gz/download}
 }
 \usage{
 food
 }
 \description{
-Etwas laengere Beschreibung des Datensatzes (hier eigene Besachreibung ergaenzen)
+A data set that relates food expenditure to income taken from Hill, Griffiths and Lim: Principles of Econometrics (4e)
 }
 \keyword{datasets}
diff --git a/man/gfc.Rd b/man/gfc.Rd
index 1cddf4110bea530e94add939db2fccae36a28297..da7e8f2a801c92ce3461024678dff25045861704 100644
--- a/man/gfc.Rd
+++ b/man/gfc.Rd
@@ -3,22 +3,26 @@
 \docType{data}
 \name{gfc}
 \alias{gfc}
-\title{Kurze Beschreibung des Datensatzes (hier eigene Beschreibung ergaenzen)}
+\title{Gross domestic products for Europe and United States of America (time-series data)}
 \format{
 A tibble with 60 rows and 3 variables:
 \describe{
-\item{quarter}{chr Angabe des Beobachtungszeitpunkts: Quartalsweise Beobachtung (4 pro Jahr) zwischen dem ersten Quartal 1995 und dem letzten Quartal 2009}
-\item{GDPE}{dbl ?}
-\item{GDPU}{dbl ?}
+\item{quarter}{chr Indication of observation date: Quarterly observation (4 per year) between the first quarter of 1995 and the last quarter of 2009.}
+\item{GDPE}{dbl Gross domestic product for the Euro Area standardized so that the value of GDP is equal to 100 in 2000.}
+\item{GDPU}{dbl Gross domestic product for the United States standardized so that the value of GDP is equal to 100 in 2000.}
 }
 }
 \source{
-\url{Quellangabe (hier beispielsweise als Link)}
+Hill, Griffiths and Lim: \verb{Principles of Econometrics (4e)}
+
+Original data: Statistical Bulletin, Reserve Bank of Australia
+
+\url{http://sourceforge.net/projects/gretl/files/datafiles/POE4data.tar.gz/download}
 }
 \usage{
 gfc
 }
 \description{
-Etwas laengere Beschreibung des Datensatzes (hier eigene Besachreibung ergaenzen)
+60 quarterly observations (1995q1 - 2009q4) of GDP for Europe and USA. Standardized so that the value of GDP is equal to 100 in 2000.
 }
 \keyword{datasets}
diff --git a/man/phillips.Rd b/man/phillips.Rd
index 1fa0185d801e6eb14d84e14c70997f5f50af2ce7..5ef63860785600880a8141525563e37ef611ad7b 100644
--- a/man/phillips.Rd
+++ b/man/phillips.Rd
@@ -3,22 +3,26 @@
 \docType{data}
 \name{phillips}
 \alias{phillips}
-\title{Kurze Beschreibung des Datensatzes (hier eigene Beschreibung ergaenzen)}
+\title{Phillips cureve data for Australia (time-series data)}
 \format{
 A tibble with 91 rows and 3 variables:
 \describe{
-\item{obs}{chr ?}
-\item{inf}{dbl ?}
-\item{u}{dbl ?}
+\item{obs}{chr Indication of observation date: Quarterly observation (4 per year) between the first quarter of 1987 and the third quarter of 2009.}
+\item{inf}{dbl Australian Inflation Rate (Percentage Change in the Consumer Price Index with an adjustment for 2000Q3 when a national sales tax was introduced)}
+\item{u}{dbl Australian Unemployment Rate (Seasonally adjusted)}
 }
 }
 \source{
-\url{Quellangabe (hier beispielsweise als Link)}
+Hill, Griffiths and Lim: \verb{Principles of Econometrics (4e)}
+
+Reserve Bank of Australia
+
+\url{http://sourceforge.net/projects/gretl/files/datafiles/POE4data.tar.gz/download}
 }
 \usage{
 phillips
 }
 \description{
-Etwas laengere Beschreibung des Datensatzes (hier eigene Besachreibung ergaenzen)
+Quarterly (1987Q1 - 2009Q3) time-series data for Australian Phillips curve.
 }
 \keyword{datasets}
diff --git a/man/qtm.Rd b/man/qtm.Rd
index a09221e22fc86e1336bcae38913e82310ad677c4..039fabc8aba16d649869fbb2de4d57612f549df0 100644
--- a/man/qtm.Rd
+++ b/man/qtm.Rd
@@ -3,22 +3,26 @@
 \docType{data}
 \name{qtm}
 \alias{qtm}
-\title{Kurze Beschreibung des Datensatzes (hier eigene Beschreibung ergaenzen)}
+\title{Quantity of money and price level (time-series data)}
 \format{
 A tibble with 180 rows and 3 variables:
 \describe{
-\item{obs}{chr ?}
-\item{m}{dbl ?}
-\item{p}{dbl ?}
+\item{obs}{chr Indication of observation date: Quarterly observation (4 per year) between the first quarter of 1961 and the last quarter of 2005.}
+\item{m}{dbl Percentage change in M3 (a measure of the quantity of money)}
+\item{p}{dbl Percentage change in the GDP deflator (a measure of aggregate price)}
 }
 }
 \source{
-\url{Quellangabe (hier beispielsweise als Link)}
+Hill, Griffiths and Lim: \verb{Principles of Econometrics (4e)}
+
+International Financial Statistics, International Monetary Fund
+
+\url{http://sourceforge.net/projects/gretl/files/datafiles/POE4data.tar.gz/download}
 }
 \usage{
 qtm
 }
 \description{
-Etwas laengere Beschreibung des Datensatzes (hier eigene Besachreibung ergaenzen)
+Data to analyze the relationship between the quantity of money (as M3) in the economy and the aggregate price level (GDP deflator).
 }
 \keyword{datasets}