Man pages matching name algorithm::lbfgs in section 3pm:

Algorithm::LBFGS.3pm.en	debian 10 / libalgorithm-lbfgs-perl
Algorithm::LBFGS.3pm.en	debian 11 / libalgorithm-lbfgs-perl
Algorithm::LBFGS.3pm.en	debian 12 / libalgorithm-lbfgs-perl