On Debian systems you can find the text of the GNU General Public Licence 2 at
/usr/share/common-licenses/GPL-2
-
-Some code to get CD info was taken from cdinfo program
-(c) 1996,1997 Gerd Knorr <kraxel@cs.tu-berlin.de> and Heiko Eissfeldt <heiko@colossus.escape.de>
-
+src/lib_cdinfo.{cpp,h}:
+"This code is from cdinfo and has the following copyrights:
+ (c) 1996,1997 Gerd Knorr <kraxel@cs.tu-berlin.de>
+ and Heiko Eissfeldt <heiko@colossus.escape.de>"
+
+cdinfo is released under the GPL:
+http://www.ibiblio.org/pub/linux/utils/disk-management/cdinfo.c
+http://www.ibiblio.org/pub/Linux/utils/disk-management/cdinfo.lsm