@article{MASLO_1972__22_4_a5, author = {\v{S}al\'at, Tibor}, title = {On {Certain} {Classes} of {Sets} of {Natural} {Numbers}}, journal = {Mathematica slovaca}, pages = {291--296}, publisher = {mathdoc}, volume = {22}, number = {4}, year = {1972}, mrnumber = {0313215}, zbl = {0249.10050}, language = {en}, url = {http://geodesic.mathdoc.fr/item/MASLO_1972__22_4_a5/} }