Books by V. F. Kagan
La Geometria no euclidiana/Non-Euclidean Geometry
Ocherki po geometrii
Ocherki po geometrii
Men of Russian Science N. Lobachevsky and his contribution to science
N. Lobachevsky and his contrib
N. Lobachevsky and his contribution to science
Lobachevskiĭ i ego geometrii︠a
Lobachevskiĭ i ego geometrii︠a︡
Lobachevskiĭ
Lobachevskiĭ