diff --git a/papers.bib b/papers.bib
index 0bedd6f..f473003 100644
--- a/papers.bib
+++ b/papers.bib
@@ -1100,3 +1100,27 @@ @Book{		  Jordan
   year		= {1989},
   pages		= {xvi+670}
 }
+
+@Article{	  Coxeter12pts,
+  author	= {Coxeter, H. S. M.},
+  title		= {Twelve points in {${\rm PG}(5,\,3)$} with {$95040$}
+		  self-transformations},
+  journal	= {Proc. Roy. Soc. London Ser. A},
+  fjournal	= {Proceedings of the Royal Society. London. Series A.
+		  Mathematical, Physical and Engineering Sciences},
+  volume	= {247},
+  year		= {1958},
+  pages		= {279--293},
+  doi		= {10.1098/rspa.1958.0184},
+}
+
+@Article{	  Sylvester1844,
+  author	= {Sylvester, J. J.},
+  title		= {Elementary researches in the analysis of combinatorial
+		  aggregation},
+  journal	= {Philosophical Magazine},
+  volume	= {24},
+  date		= {1844},
+  pages		= {285--296},
+  url		= {https://math.ucr.edu/home/baez/mathematical/sylvester_combinatorial_aggregation.pdf}
+}