참고문헌
- Sets, Lattices and Boolean Algebras Abbott, J.C.
- Sci. Math. Japon. On ideals in subtraction algebras Jun, Y.B.;Kim, H.S.
- Sci. Math. Japon. Ideal theory of subtraction algebras Jun, Y.B.;Kim, H.S.;Roh, E.H.
- Internat. J. Math. & Math. Sci. Prime and irreducible ideals in subtraction algebras Jun, Y.B.;Kim, K.H.
- Math. Bohemica v.128 Subtraction algebras and BCK-algebras Kim, Y.H.;Kim, H.S.
- Comm. in Algebra v.20 Difference Semigroups Schein, B.M.
- Math. Bohemica v.120 Subtraction Semigroups Zelinka, B.