Bug#44023: apt: No documentation on putting "some 'source' uris" in my sources.list

[<dvdeug@x8b4e53cd.dhcp.okstate.edu>]

Package: apt
Version: 0.3.11
Severity: wishlist

apt-get source keeps telling me to put some source uris in my sources.list.
Unfortunetly, man sources.list doesn't mention what a source uri is. 
/usr/doc/users-guide.txt.gz doesn't mention apt-get source or what a source
uri is either. This is a documentation deficency that needs help.

My /etc/apt/sources.list --
deb http://http.us.debian.org/debian unstable main contrib non-free 
deb http://non-us.debian.org/debian-non-US unstable non-US/main non-US/contrib non-US/non-free 

-- System Information
Debian Release: potato
Kernel Version: Linux x8b4e53cd 2.2.12 #2 Tue Aug 31 18:43:21 CDT 1999 i686 unknown

Versions of the packages apt depends on:
ii  libc6           2.1.2-0pre12   GNU C Library: Shared libraries and timezone
ii  libstdc++2.9-gl 2.91.66-2      The GNU stdc++ library (EGCS version)