diff --git a/Nef_2/doc_tex/Nef_2/PkgDescription.tex b/Nef_2/doc_tex/Nef_2/PkgDescription.tex
index ce59c16cdfe..f1b4e586793 100644
--- a/Nef_2/doc_tex/Nef_2/PkgDescription.tex
+++ b/Nef_2/doc_tex/Nef_2/PkgDescription.tex
@@ -1,5 +1,6 @@
 
 \begin{ccPkgDescription}{2D Boolean Operations on Nef Polygons \label{Pkg:Nef2}}
+\ccHowToCite{cgal:s-bonp2-06}
 \ccPkgSummary{
 A Nef polygon is any set that can be obtained from a
 finite set of open halfspaces by set complement and set intersection