Acknowledgment of priority: “On some problems of Mąkowski–Schinzel and Erdős concerning the arithmetical functions $\phi$ and $\sigma$” (Colloq. Math. 92 (2002), 111–130)
Tom 126 / 2012
Colloquium Mathematicum 126 (2012), 139
DOI: 10.4064/cm126-1-10
