@article{SF_1984__29_134686,
     author = {F. Linton},
     title = {Categories of algebraic systems.},
     journal = {Semigroup forum},
     pages = {247--250},
     year = {1984},
     volume = {29},
     url = {http://geodesic.mathdoc.fr/item/SF_1984__29_134686/}
}