1. Abromovich, M.: Handbook of Mathematical Functions. New York: Dover 1965
2. Barban, M.B.: Linnik's ?large sieve? and a limit theorem for the class number of ideals of an imaginary quadratic field. Izv. Akad. Nauk SSSR Ser. Mat.26, 573?580 (1962)
3. Burgess, D.A.: On character sums andL-series, II. Proc. Lond. Math. Soc.13, 524?536 (1963)
4. Davenport, H.: Multiplicative Number Theory. Second Edition, pp. 105?106. Berlin-Heidelberg-New York: Springer 1980
5. Gauss, C.F.: Disquisitiones Arithmeticae. New Haven-London: Yale University Press 1966