Binary relations and reduced hypergroups. - Irina Cristea; Mirela Stefanescu (Discret. Math., 2008)

On the fuzzy grade of hypergroups. - Mirela Stefanescu; Irina Cristea (Fuzzy Sets Syst., 2008)

Hypergroups and n-ary relations. - Irina Cristea; Mirela Stefanescu (Eur. J. Comb., 2010)

About the fundamental relations defined on the hypergroupoids associated with binary relations. - Irina Cristea; Mirela Stefanescu; Carmen Angheluta (Eur. J. Comb., 2011)