1. Equational classes of modular lattices;Baker, Kirby A.;Pacific J. Math.,1969
2. P. Crawley and R. P. Dilworth, Algebraic theory of lattices, Prentice-Hall, Englewood Cliffs, N. J., 1973.
3. Component subsets of the free lattice on 𝑛 generators;Dean, Richard A.;Proc. Amer. Math. Soc.,1956
4. The arithmetical theory of Birkhoff lattices;Dilworth, R. P.;Duke Math. J.,1941
5. Planar sublattices of 𝐹𝑀(4);Freese, Ralph;Algebra Universalis,1976