Man pages matching name perl4::corelibs in section 3pm:

Perl4::CoreLibs.3pm.en	debian 10 / libperl4-corelibs-perl
Perl4::CoreLibs.3pm.en	debian 11 / libperl4-corelibs-perl
Perl4::CoreLibs.3pm.en	debian 12 / libperl4-corelibs-perl