1. B. A. Venkov, Elementary Number Theory, Wolters-Noordhoff, Groningen (1970).
2. A. I. Vinogradov and Yu. V. Linnik, ?Hyperelliptic curves and the least prime quadratic residue,? Dokl. Akad. Nauk SSSR,168, No. 2, 259?261 (1966).
3. A. M. Istamov, ?Asymptotics of second-order integral matrices lying in a given hyperbolic region and belonging to a given residue class,? J. Sov. Math.,19, No. 2 (1982).
4. Yu. V. Linnik, ?On the representations of large numbers by positive, ternary quadratic forms,? Izv. Akad. Nauk SSSR, Ser. Mat.,4, Nos. 4/5, 363?402 (1940).
5. Yu. V. Linnik, ?Some applications of the Lobachevskii geometry to the theory of binary quadratic forms,? Dokl. Akad. Nauk SSSR,93, No. 6, 973?974 (1953).