diff --git a/tex/ch0.tex b/tex/ch0.tex
index dbd11a37..9ae5b402 100644
--- a/tex/ch0.tex
+++ b/tex/ch0.tex
@@ -42,15 +42,16 @@ \chapter*{Introduction}
 infinitude of prime numbers, or the correctness of the Euclidean's
 division algorithm, in a few lines of proof text.
 
-\paragraph{Acknowledgments.} The authors wish to thank
-Reynald Affeldt, Guillaume Allais, Sophie Bernard, Alain Giorgetti,
-Laurence Rideau, Lionel Rieg, Damien Rouhling, Michael Soegtrop for
-their comments on earlier versions of this text. They are specially
-grateful to Simon Boulier, Arthur Charguéraud, Florent Hivert, Pierre
-Jouvelot, Darij Grinberg, Guillaume Melquiond, Michael Nahas, Julien
-Narboux, Anton Trunov, Yamamoto Mitsuharu and Prashanth Mundkur for
-their careful proofreading and for their suggestions. Many thanks to
-Hanna for the illustrations.
+\paragraph{Acknowledgments.}
+We thank Yves Bertot and Georges Gonthier, for contributing the first
+and the last chapter of this book. We wish to thank Reynald Affeldt,
+Guillaume Allais, Sophie Bernard, Simon Boulier, Cyril Cohen, Arthur
+Charguéraud, Alain Giorgetti, Darij Grinberg, Florent Hivert, Pierre
+Jouvelot, Marisa Kirisame, Guillaume Melquiond, Sebastian Miele,
+Yamamoto Mitsuharu, Prashanth Mundkur, Michael Nahas, Julien Narboux,
+Laurence Rideau, Lionel Rieg, Damien Rouhling, Michael Soegtrop,
+Laurent Théry, and Anton Trunov for their careful proofreading and for
+their suggestions. Many thanks to Hanna for the illustrations.
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 \section*{Structure of the book}
diff --git a/tex/main.tex b/tex/main.tex
index 8e0946a5..51b0d232 100755
--- a/tex/main.tex
+++ b/tex/main.tex
@@ -97,7 +97,7 @@
 ~\vfill
 \thispagestyle{empty}
 
-\noindent Copyright \copyright\ 2018 Assia Mahboubi and Enrico Tassi and Yves Bertot and Georges Gonthier\\
+\noindent Copyright \copyright\ 2020 Yves Bertot and Georges Gonthier and Assia Mahboubi and Enrico Tassi\\
 
 % \noindent \textsc{Published by us}\\ % Publisher