Added links to references and citation bib files

README.md

@@ -81,6 +81,8 @@ http://localhost:8888/lab?token=73e08328facee92d67a8dd2b587b6fa7cb8a3e3323d653f8
 Please cite **Py4HIP** as follows:\
 *Bott, J., Benoit, L., Koltzer, N., Anikiev, D. (2022): Py4HIP: Python tool for Heat-In-Place calculations. V. 1. GFZ Data Services, https://doi.org/10.5880/GFZ.4.5.2022.001*
 
+Citation bib file: [CITATION.bib](./CITATION.bib)
+
 ## Authors and contributions
 See also the list of [authors](../AUTHORS.md) who participated in this project.
 If you what to contribute to this project please follow the [contributing guidelines](../CONTRIBUTING.md).
@@ -115,5 +117,7 @@ https://doi.org/10.1017/S0016774600000433
 Vosteen, H.-D., & Schellschmidt, R. (2003). Influence of temperature on thermal conductivity, thermal capacity and thermal diffusivity for different types of rock. Physics and Chemistry of the Earth, Parts A/B/C, 28(9-11), 499-509.
 https://doi.org/10.1016/S1474-7065(03)00069-X
 
+References are available as [a bib file](./references.bib).
+
 ## Contact
 [Judith Bott](@sippel): judith.bott@gfz-potsdam.de