apt fedora core 4

[pipe_24]

he instalado apt y me dice lo siguiente
[root@Informatica ~]# cd /
[root@Informatica /]# cd descarga
[root@Informatica descarga]# rpm -Uvh apt-0.5.15cnc7-6.fc4.i386.rpm
warning: apt-0.5.15cnc7-6.fc4.i386.rpm: Header V3 DSA signature: NOKEY, key ID 1ac70ce6
Preparing... ########################################### [100%]
1:apt ########################################### [100%]
[root@Informatica descarga]# apt-get source php
You don't seem to have one or more of the needed GPG keys in your RPM database.
Importing them now...
Leyendo listas de paquetes... Done
Construyendo árbol de dependencias... Done
E: You must put some 'source' URIs in your sources.list
[root@Informatica descarga]#
como haga ahora para poder actualizar???