@article{10_4064_aa_51_4_321_333,
     author = {Y.-F. P\'etermann},
     title = {Changes of sign of error terms related to {Euler's} function and to divisor functions {II}},
     journal = {Acta Arithmetica},
     pages = {321--333},
     publisher = {mathdoc},
     volume = {51},
     number = {4},
     year = {1988},
     doi = {10.4064/aa-51-4-321-333},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/aa-51-4-321-333/}
}