@article{JTNB_2004__16_1_107_0,
     author = {von zur Gathen, Joachim and Knopfmacher, Arnold and Luca, Florian and Lucht, Lutz G. and Shparlinski, Igor E.},
     title = {Average order in cyclic groups},
     journal = {Journal de th\'eorie des nombres de Bordeaux},
     pages = {107--123},
     publisher = {Universit\'e Bordeaux 1},
     volume = {16},
     number = {1},
     year = {2004},
     doi = {10.5802/jtnb.436},
     zbl = {1079.11003},
     mrnumber = {2145575},
     language = {en},
     url = {http://archive.numdam.org/articles/10.5802/jtnb.436/}
}