참고문헌
- G. Birkhoff, Lattice Theory, Ame. Math. Soc. Collq. Publ. Vol. 25, providence, R. L, 1967.
- I. Chajda and J. Rachunek, Forbidden Configurations for Distributive and Modular Ordered Sets, Order 5 (1989), 407-423. https://doi.org/10.1007/BF00353659
- B. A. Davey and H. A. Priestley, Introduction to Lattices and Order, Cambridge University Press, 1990.
- Y. H. Hong, S. J. Lim and S. H. Shin, Modularity and Distributivity of Ordered Sets, J. Nat. Sci. Sookmyung Women's Univ. 13 (2002), 83-87.
- M. Kolibiar, Modular Ordered sets, Math. Slovaca, 44 (1994), no. 2, 139-141.