final version, submitting.

Former-commit-id: 09c7e4204f837946dc564031f34757302ac5bfbb

theory/paper_algs/sph.bib

@@ -308,6 +308,17 @@
     year = {2011}
     }
     
+@article{ref:Springel2005,
+  title={Simulations of the formation, evolution and clustering of galaxies and quasars},
+  author={Springel, Volker and White, Simon DM and Jenkins, Adrian and Frenk, Carlos S and Yoshida, Naoki and Gao, Liang and Navarro, Julio and Thacker, Robert and Croton, Darren and Helly, John and others},
+  journal={nature},
+  volume={435},
+  number={7042},
+  pages={629--636},
+  year={2005},
+  publisher={Nature Publishing Group}
+}
+
 @article{ref:Gonnet2012,
     author = "Gonnet, Pedro",
     title = "Pairwise {V}erlet lists: Combining cell lists and {V}erlet lists to improve memory locality and parallelism",