Some remarks on modularity in prealgebraic and algebraic lattices Gerd Richter (1991) Beiträge zur Algebra und Geometrie = Contributions to algebra and geometry
Some special subsets of intervals of a locally finite locally semi-modular, local lattice. Dennis A. McDonald (1975) Journal für die reine und angewandte Mathematik
Subalgebra modular, distributive and boolean varieties of semigroups Bedřich Pondělíček (1992) Czechoslovak Mathematical Journal