@article{AMBP_1996__3_2_67_0, author = {Mario De Salvo and Domenico Freni and Giovanni Lo Faro}, title = {On the hypergroups with four proper pairs and without scalars}, journal = {Annales math\'ematiques Blaise Pascal}, pages = {67--109}, publisher = {Laboratoires de Math\'ematiques Pures et Appliqu\'ees de l'Universit\'e Blaise Pascal}, volume = {3}, number = {2}, year = {1996}, zbl = {0869.20049}, mrnumber = {1435317}, language = {en}, url = {https://ambp.centre-mersenne.org/item/AMBP_1996__3_2_67_0/} }