Packages shown on packages.ubuntulinux.org not available for install?

[Alexander Skwar]

Hello!

As I've now finally managed to install Ubuntu, I'd now
like to install some software. Eg. "elinks" <http://packages.ubuntulinux.org/dapper/web/elinks>
or "f-spot" <http://packages.ubuntulinux.org/dapper/gnome/f-spot>.
Now I tried to install those programs:

alexander at knospe:~$ LC_ALL=C sudo apt-get install f-spot
Reading package lists... Done
Building dependency tree... Done
E: Couldn't find package f-spot
alexander at knospe:~$ LC_ALL=C sudo apt-get install elinks
Reading package lists... Done
Building dependency tree... Done
E: Couldn't find package elinks

Why's that? Why are f-spot and elinks not offered for
installation?

Among other things, I've got the following in /etc/apt/sources.list:

deb http://de.archive.ubuntu.com/ubuntu/ dapper universe
deb http://de.archive.ubuntu.com/ubuntu/ dapper-backports main restricted universe multiverse

Thanks,
Alexander