@article{IVM_1999_11_a8,
     author = {R. Zh. Aleev and G. A. Panina},
     title = {The units of cyclic groups of orders~7 and~9},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {81--84},
     year = {1999},
     number = {11},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1999_11_a8/}
}