1. Eric Bach, Richard Lukes, Jeffrey Shallit, and H. C. Williams, Results and estimates on pseudopowers, Math. Comp. 65 (1996), no. 216, 1737–1747. MR1355005
2. Alina Carmen Cojocaru and M. Ram Murty, An introduction to sieve methods and their applications, London Mathematical Society Student Texts, vol. 66, Cambridge University Press, Cambridge, 2006. MR2200366
3. Chantal David and Francesco Pappalardi, Average Frobenius distributions of elliptic curves, Internat. Math. Res. Notices 4 (1999), 165–183. MR1677267
4. Adam Tyler Felix and M. Ram Murty, A problem of Fomenko’s related to Artin’s conjecture, Int. J. Number Theory 8 (2012), no. 7, 1687–1723. MR2968946
5. O. M. Fomenko, Class numbers of indefinite binary quadratic forms, Zap. Nauchn. Sem. S.-Peterburg. Otdel. Mat. Inst. Steklov. (POMI) 276 (2001), no. Anal. Teor. Chisel i Teor. Funkts. 17, 312–333, 354–355 (Russian, with Russian summary); English transl., J. Math. Sci. (N. Y.) 118 (2003), no. 1, 4918–4932. MR1850375