1. T. Garibe, ?Surfaces with constant exterior and interior geometry in E4,? Ukr. Geom. Sb.,24, 12?18 (1981).
2. T. Garibe, ?Two-dimensional surfaces with constant exterior geometry in E5,? Ukr. Geom. Sb.,25, 11?22 (1982).
3. S. B. Kadomtsev, ?On a certain property of the group of motions of the Lobachevskii plane,? Mat. Zametki,35, No. 1, 107?110 (1984).
4. L. Bieberbach, ?Eine singularitatensfreie Flache konstanter negativer Krummung im Hilbertischen Raum,? Comm. Math. Helv.,4, 248?255 (1932).