Ratio Mathematica – n. 12 / 1997

Les hypertreillis tres fins 
C. Gutan,  pag. 3
 

Properties of hyperproducts and the relation b in quasi hypergroups  
M. Gutan,  pag. 19

Fuzzy sub-f-polygroups 
A. Hasankhani e M. M. Zahedi,  pag. 35
 
M-polysymmetrical hyperrings 
J. Mittas e C. N. Yatras,  pag. 45
 
Over the construction of an hyperstructure of quotients for a moltiplicative hyperring 
R. Procesi e R. Rota,  pag. 66
 
Une note sur les groupes permutables 
V. Leoreanu,  pag. 73
 

Hyperstructures as tool to compare urban projects 
B. Ferri e A. Maturo,  pag. 79

Weak hyperstructures on small sets 
T. Vougiouklis, S. Spartalis e M. Kessoglides,  pag. 90
 

Hyper BCK-algebra 
M. Bolurian e A. Hasankhani,  pag. 97