1. P. Crawley and R. P. Dilworth, Algebraic theory of lattices, Prentice-Hall, Englewood Cliffs, N. J., 1973.
2. Splitting algebras and a weak notion of projectivity;Day, Alan;Algebra Universalis,1975
3. Planar sublattices of 𝐹𝑀(4);Freese, Ralph;Algebra Universalis,1976
4. The variety of modular lattices is not generated by its finite members;Freese, Ralph;Trans. Amer. Math. Soc.,1979
5. Congruence modularity implies the Arguesian identity;Freese, Ralph;Algebra Universalis,1976