@article{NSJOM_1998_28_2a_10,
     author = {S. 

 Crvenkovi\'c and I. Dolinka},
     title = {Undecidable varieties with solvable word problems - {III} (a semigroup 

 variety)},
     journal = {Novi Sad Journal of Mathematics},
     pages = {109-117},
     year = {1998},
     volume = {28},
     number = {2},
     url = {http://geodesic.mathdoc.fr/item/NSJOM_1998_28_2a_10/}
}