%0 Journal Article %A Y.-F. Pétermann %T Changes of sign of error terms related to Euler's function and to divisor functions II %J Acta Arithmetica %D 1988 %P 321-333 %V 51 %N 4 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.4064/aa-51-4-321-333/ %R 10.4064/aa-51-4-321-333 %G en %F 10_4064_aa_51_4_321_333