@article{VMUMM_1987_2_a19,
     author = {A. V. Abramyan},
     title = {On circular parameters},
     journal = {Vestnik Moskovskogo universiteta. Matematika, mehanika},
     pages = {73--75},
     publisher = {mathdoc},
     number = {2},
     year = {1987},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMUMM_1987_2_a19/}
}