Fix link in README.md

README.md

@@ -13,4 +13,4 @@ To get started, have a look at ```Example.py``` as well as ```ExampleTransients.
 
 ## References
 
-E. Garutti, R. Klanner, J. Rolph, J. Schwandt: _Simulation of the response of SiPMs; Part I: Without saturation effects_.  [doi.org/10.1016/j.nima.2021.165853](https://doi.org/10.1016/j.nima.2023.168544)
+E. Garutti, R. Klanner, J. Rolph, J. Schwandt: _Simulation of the response of SiPMs; Part I: Without saturation effects_.  [doi.org/10.1016/j.nima.2021.165853](https://doi.org/10.1016/j.nima.2021.165853)