@article{CHEB_2018_19_3_a9,
     author = {N. N. Dobrovolsky and A. O. Kalinina and M. N. Dobrovolsky and N. M. Dobrovolsky},
     title = {On the monoid of quadratic residues},
     journal = {\v{C}eby\v{s}evskij sbornik},
     pages = {95--108},
     publisher = {mathdoc},
     volume = {19},
     number = {3},
     year = {2018},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/CHEB_2018_19_3_a9/}
}