diff --git a/Packages/Interval_arithmetic/doc_tex/NumberTypeSupport_ref/Interval.tex b/Packages/Interval_arithmetic/doc_tex/NumberTypeSupport_ref/Interval.tex
index eeaca3aef5e..b23317d3192 100644
--- a/Packages/Interval_arithmetic/doc_tex/NumberTypeSupport_ref/Interval.tex
+++ b/Packages/Interval_arithmetic/doc_tex/NumberTypeSupport_ref/Interval.tex
@@ -27,8 +27,7 @@ the roundoff errors made by floating point computations.
 You can choose the behaviour of your program depending on these errors; that
 is what is done for the filtered robust predicates (see Section~\ref{filter}).
 You can find more theoretical information on this topic in
-\cite{bbp-iayea-98}.
-% \cite{bbp-iayed-98scg}. % worked here, but changed by Remco.
+\cite{bbp-iayed-01}.
 
 %\ccDefinition
 Interval arithmetic is a large concept and we will only consider here a 
diff --git a/Packages/Interval_arithmetic/doc_tex/support/NumberTypeSupport_ref/Interval.tex b/Packages/Interval_arithmetic/doc_tex/support/NumberTypeSupport_ref/Interval.tex
index eeaca3aef5e..b23317d3192 100644
--- a/Packages/Interval_arithmetic/doc_tex/support/NumberTypeSupport_ref/Interval.tex
+++ b/Packages/Interval_arithmetic/doc_tex/support/NumberTypeSupport_ref/Interval.tex
@@ -27,8 +27,7 @@ the roundoff errors made by floating point computations.
 You can choose the behaviour of your program depending on these errors; that
 is what is done for the filtered robust predicates (see Section~\ref{filter}).
 You can find more theoretical information on this topic in
-\cite{bbp-iayea-98}.
-% \cite{bbp-iayed-98scg}. % worked here, but changed by Remco.
+\cite{bbp-iayed-01}.
 
 %\ccDefinition
 Interval arithmetic is a large concept and we will only consider here a