@article{JTNB_1998__10_1_203_0,
     author = {P\'etermann, Y.-F. S.},
     title = {On an estimate of {Walfisz} and {Saltykov} for an error term related to the {Euler} function},
     journal = {Journal de th\'eorie des nombres de Bordeaux},
     pages = {203--236},
     publisher = {Universit\'e Bordeaux I},
     volume = {10},
     number = {1},
     year = {1998},
     mrnumber = {1827292},
     zbl = {0917.11047},
     language = {en},
     url = {http://www.numdam.org/item/JTNB_1998__10_1_203_0/}
}