2 citations to https://www.mathnet.ru/rus/mzm3681

1. Dietmann R. Elsholtz Ch. Shparlinski I.E., “Prescribing the Binary Digits of Squarefree Numbers and Quadratic Residues”, Trans. Am. Math. Soc., 369:12 (2017), 8369–8388          
2. Shparlinski I.E., “Modular hyperbolas”, Jap. J. Math., 7:2 (2012), 235–294