Voir la notice de l'article provenant de la source European Digital Mathematics Library
@article{SF_1977__14_186357, author = {H. J\"urgensen and P. Wick}, title = {Die {Halbgruppen} der {Ordnungen} = <7 .}, journal = {Semigroup forum}, pages = {69--80}, publisher = {mathdoc}, volume = {14}, year = {1977}, zbl = {0363.20050}, url = {http://geodesic.mathdoc.fr/item/SF_1977__14_186357/} }
H. Jürgensen; P. Wick. Die Halbgruppen der Ordnungen = <7 .. Semigroup forum, Tome 14 (1977), pp. 69-80. http://geodesic.mathdoc.fr/item/SF_1977__14_186357/