G. Grätzer

Revisiting the Representation Theorem of Finite Distributive Lattices with Principal Congruences. A Proof-By-Picture Approach

G. Grätzer, H. Lakser, H. Lakser, 2021, 2104.13835.

Joins and Direct Products of Equational Classes

G. Grätzer, H. Lakser, J. Płonka, 1969, Canadian Mathematical Bulletin.

A note on the implicational class generated by a class of structures

G. Grätzer, H. Lakser, H. Lakser, 1973 .