1 Clifford A H. Extensions of semigroups. Trans Amer Math Soc, 1950, 68: 165-173
2 Tamura T. Commutative nonpotent Archimedean semigroups with cancellation law. J Gakugei Tokushima
Univ, 1957, 8: 5-11
3 Tamura T. Basic study of N-semigroups and their homomorphism. Semigroup Forum, 1974, 8: 21-50
4 Tamura T. Basic study of N-semigroups and their homomorphisms II. Semigroup Forum, 1975, 10: 250-
261
5 Levin R. On commutative, nonpotent, Archimedean semigroups. Pacific J Math, 1968, 27: 365-371
6 Chrislock J. On medial semigroups. J Algebra, 1969, 12: 1-9
7 Clifford A H, Preston G B. The algebraic theory of semigroups. Amer Math Soc, Providence, 1961
8 Gilmer R. Commutative semigroup rings. Chicago lectures in Mathematics, 1984
9 Grillet P A. Semigroups. An Introduction to the structure theory. Dekker, 1995
10 R´edei L. The theory of finitely generated commutative semigroups. Oxford, Edimburg, New York: Perg-
amon, 1965
11 Rosales J C, Garc´?a-S´anchez P A. Finitely generated commutative monoids. New York: Nova Science
Publishers, 1999
12 Rosales J C, Garc´?a-S´anchez P A, Urbano-Blanco J M. On presentations of commutative monoids. Internat
J Algebra Comput, 1999, 9(5): 539-553 |