1. Baranovskii E. P., 1967, "Packings, coverings, partitions and some other dispositions in the spaces of fixed curvature IN. Algebra. Topology. Geometry. M. pp. 189–225.
2. Venkov B. A., 1945, "On Markov extremal problem for undeterminate ternary forms Izv. AN SSSR. Math., vol. 9, no 6. pp.429–494.
3. Vetchinkin N. M., 1980, "Uniquness of the classes of positiv quadratic forms, on which it is achieved the values of the Ermit constances for 6 <= n <= 8 Trudy MIAN, vol. 152. pp. 34–86.
4. Delone B. N., 1937, 1938, "The geometry of the positive quadratic forms UMN, iss. 3, pp. 16–62; iss 4. pp. 102–164.
5. Delone B. N., 1947, The Petersburg school of the numbers theory M–P, 422 p.