diff --git a/project_description.md b/project_description.md
index dfa2a6ca61b3fe9f8e80b280c7f90cb3740ee6fd..7828cc112fc96af5618b05b1bd11eb64a9aa42e3 100644
--- a/project_description.md
+++ b/project_description.md
@@ -34,6 +34,10 @@ Start of july - End of August (exact dates YTBD)
 * http://adsabs.harvard.edu/abs/2013MNRAS.432.2779B
 * http://adsabs.harvard.edu/abs/2019arXiv190207718B
 * [Website containing some lectures on N-body integration](http://silkroad.bao.ac.cn/web/index.php/seminars/lectures)
+* http://epubs.surrey.ac.uk/812065/1/MNRAS-2016-Peuten-2333-42.pdf 
+* https://arxiv.org/pdf/1712.03979.pdf
+* https://arxiv.org/pdf/1708.09530.pdf
+
 
 ## Some watching material:
 * https://www.cita.utoronto.ca/presentation-archive/?talk_id=745