diff --git a/doc/ref/grplib.xml b/doc/ref/grplib.xml
index d7abb2ac48..bd0df6693d 100644
--- a/doc/ref/grplib.xml
+++ b/doc/ref/grplib.xml
@@ -313,12 +313,14 @@ be noted that  their book contains a  lot of further information for many
 of the library groups.  So we would like  to recommend  it to any  ⪆
 user who is interested in the groups.
 Two additional groups omitted from the book <Q>Perfect Groups</Q> have also
-been included.
+been included. These groups -- one of order 450000 with a factor group of
+type <M>A_6</M> and the one of order 962280 -- were found by Jack Schmidt in
+2005.
 <P/>
 The library of these has been brought into &GAP; format by Volkmar Felsch.
 <P/>
-The perfect groups of size less than <M>10^6</M>which were missing in the work of Holt
-and Plesken have been enumerated by Alexander
+The perfect groups of size less than <M>10^6</M> which had not been
+classified in the work of Holt and Plesken have been enumerated by Alexander
 Hulpke. They are stored directly and provide less construction information
 in their names.
 <P/>