add CITATIONS.bib

Author: michael-petersen

CITATIONS.bib

@@ -0,0 +1,36 @@
+@ARTICLE{2022MNRAS.510.6201P,
+       author = {{Petersen}, Michael S. and {Weinberg}, Martin D. and {Katz}, Neal},
+        title = "{EXP: N-body integration using basis function expansions}",
+      journal = {\mnras},
+     keywords = {methods: numerical, Galaxy: halo, galaxies: haloes, galaxies: kinematics and dynamics, galaxies: structure, Astrophysics - Astrophysics of Galaxies, Astrophysics - Instrumentation and Methods for Astrophysics},
+         year = 2022,
+        month = mar,
+       volume = {510},
+       number = {4},
+        pages = {6201-6217},
+          doi = {10.1093/mnras/stab3639},
+archivePrefix = {arXiv},
+       eprint = {2104.14577},
+ primaryClass = {astro-ph.GA},
+       adsurl = {https://ui.adsabs.harvard.edu/abs/2022MNRAS.510.6201P},
+      adsnote = {Provided by the SAO/NASA Astrophysics Data System}
+}
+
+@ARTICLE{1999AJ....117..629W,
+       author = {{Weinberg}, Martin D.},
+        title = "{An Adaptive Algorithm for N-Body Field Expansions}",
+      journal = {\aj},
+     keywords = {CELESTIAL MECHANICS, STELLAR DYNAMICS, GALAXIES: STRUCTURE, GALAXY: STRUCTURE, METHODS: NUMERICAL, Astrophysics},
+         year = 1999,
+        month = jan,
+       volume = {117},
+       number = {1},
+        pages = {629-637},
+          doi = {10.1086/300669},
+archivePrefix = {arXiv},
+       eprint = {astro-ph/9805357},
+ primaryClass = {astro-ph},
+       adsurl = {https://ui.adsabs.harvard.edu/abs/1999AJ....117..629W},
+      adsnote = {Provided by the SAO/NASA Astrophysics Data System}
+}
+

CONTRIBUTING.md

@@ -2,7 +2,8 @@
 
 There are many ways to contribute to EXP. Here are some of them:
 
--   Blog about EXP. Cite the EXP published papers. Tell the world how
+-   Blog about EXP. Cite the EXP published papers (using 
+    the papers in `CITATIONS.bib`). Tell the world how
     you're using EXP. This will help newcomers with more examples and
     will help the EXP project to increase its visibility.
 -   Report bugs and request features in the [issue