%0 Journal Article
%A Florian Luca
%A Carl Pomerance
%T On some problems of M/akowski–Schinzel and Erdős
concerning the arithmetical functions $\phi $ and $\sigma $
%J Colloquium Mathematicum
%D 2002
%P 111-130
%V 92
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/articles/10.4064/cm92-1-10/
%R 10.4064/cm92-1-10
%G en
%F 10_4064_cm92_1_10