Man pages matching name xml::rss::libxml::implbase in section 3pm:

XML::RSS::LibXML::ImplBase.3pm.en	debian 10 / libxml-rss-libxml-perl
XML::RSS::LibXML::ImplBase.3pm.en	debian 11 / libxml-rss-libxml-perl
XML::RSS::LibXML::ImplBase.3pm.en	debian 12 / libxml-rss-libxml-perl