%0 Journal Article %A Kwara Nantomah %T Monotonicity and convexity properties of the Nielsen's $\beta$-function %J Problemy analiza %D 2017 %P 81-93 %V 6 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/item/PA_2017_6_2_a4/ %G en %F PA_2017_6_2_a4