Расслояемые пары конгруэнций фигур

The different types of stratifiable pair of congruences (two-parametric families) of figures are defined in three-dimensional projective space: induced stratifiable pair, curvilinear stratifiable pair, two-sided stratifiable pair.
The stratifiable pair of congruences of conics and stratifiable pair formed by congruence of conics and congruence of lines are examined in detail.
Библ. 5.