Update p4est references.

diff --git a/9.6/paper.tex b/9.6/paper.tex
index 7a230e67d6d68bcaa2b716d2d2a7e500178529dc..56d067dc591da78afe84725e2d1d27d847c75401 100644 (file)
--- a/9.6/paper.tex
+++ b/9.6/paper.tex
@@ -368,7 +368,7 @@ following:
     \item MUMPS \cite{amestoy2001mumps,amestoy2019mumps}
     \item muparser \cite{muparser-web-page}
     \item OpenCASCADE \cite{opencascade-web-page}
-    \item p4est \cite{burstedde2011p4est,burstedde2020parallel}
+    \item p4est \cite{burstedde2011p4est}
     \item PETSc \cite{petsc-user-ref,petsc-web-page}
     \item ROL \cite{ridzal2014rol}
     \item ScaLAPACK \cite{blackford1997scalapack}