installing package

[Raymond Gree <raymond.gree@wanadoo.fr>]

Bonsoir,
j'essaie d'installer lprng et j'ai le message suivant:

debian-server:/# apt-get install lprng lprngtool magicfilter
Reading Package Lists... Done
Building Dependency Tree... Done
Package lprng has no available version, but exists in the database.
This typically means that the package was mentioned in a dependency and
never uploaded, has been obsoleted or is not available with the contents
of sources.list
E: Package lprng has no installation candidate

le contenu de mon sources.conf est:

deb ftp://172.20.1.20/pub/debian stable main  
deb http://non-us.debian.org/debian-non-US stable/non-US main
deb-src http://non-us.debian.org/debian-non-US stable/non-US main
deb http://security.debian.org/ stable/updates main

merci pour votre aide
Ray