Man pages matching name math::vector::real::kdtree in section 3pm:

Math::Vector::Real::kdTree.3pm.en	debian 10 / libmath-vector-real-kdtree-perl
Math::Vector::Real::kdTree.3pm.en	debian 11 / libmath-vector-real-kdtree-perl
Math::Vector::Real::kdTree.3pm.en	debian 12 / libmath-vector-real-kdtree-perl