@article{SF_1974__8_134022,
     author = {Takayuki Tamura},
     title = {Basic study of ...-semigroups and their homomorphisms.},
     journal = {Semigroup forum},
     pages = {21--50},
     year = {1974},
     volume = {8},
     zbl = {0275.20110},
     url = {http://geodesic.mathdoc.fr/item/SF_1974__8_134022/}
}