Man pages matching name graphics::gnuplotif in section 3pm:

Graphics::GnuplotIF.3pm.en	debian 10 / libgraphics-gnuplotif-perl
Graphics::GnuplotIF.3pm.en	debian 11 / libgraphics-gnuplotif-perl
Graphics::GnuplotIF.3pm.en	debian 12 / libgraphics-gnuplotif-perl