@article{NSJOM_1981_11_Nonea_20,
     author = {\v{C}upona 

 Georgi and Crvenkovi\'c Sini\v{s}a and Vojvodi\'c Gradimir},
     title = {Subalgebras of commutative semigroup satisfying xr+xr+m},
     journal = {Novi Sad Journal of Mathematics},
     pages = {217-230},
     year = {1981},
     volume = {11},
     url = {http://geodesic.mathdoc.fr/item/NSJOM_1981_11_Nonea_20/}
}