@article{MOMA_1976__82_177775,
     author = {S. Knapowski and P. Tur\'an},
     title = {On the {Sign} {Changes} of (...(x) - lix). {II.}},
     journal = {Monatshefte f\"ur Mathematik},
     pages = {163--176},
     publisher = {mathdoc},
     volume = {82},
     year = {1976},
     zbl = {0342.10025},
     url = {http://geodesic.mathdoc.fr/item/MOMA_1976__82_177775/}
}