@article{ELMA_1971__26_141006,
     author = {D. Suryanarayana},
     title = {Semi-k-free {Integers.}},
     journal = {Elemente der Mathematik},
     pages = {39--40},
     publisher = {mathdoc},
     volume = {26},
     year = {1971},
     zbl = {0211.38002},
     url = {http://geodesic.mathdoc.fr/item/ELMA_1971__26_141006/}
}