1. I. A. Baltag and A. M. Zamorzaev, “On the theory of Fedorov groups and of regular partitionings on a pseudo-Euclidean plane,” Uch. Zap. Kishinevsk. Univ., 82:82–96 (1965).
2. E. P. Baranovskii, “The minima of the density of a lattice covering of a space by equal spheres,” Uch. Zap. Ivanovsk. Gos. Ped. Inst., 34: 71–76 (1963).
3. E. P. Baranovskii, “The filling of n-dimensional Euclidean spaces by equal spheres. I,” Izv. Vysshikh. Uchebn. Zavedenii, Matematika, No. 2, pp. 14–24(1964).
4. E. P. Baranovskii, “Local minima of the density of the lattice coverings of a four-dimensional Euclidean space by equal spheres,” Dokl. Akad. Nauk, SSSR, 164(1): 13–15 (1965).
5. E. P. Baranovskii, “Local minima of the density of the lattice covering of a four-dimensional Euclidean space by equal spheres,” Sibirsk. Mat. Zh., 7(5): 974–1001 (1966).