ABSTRACT. Sets regular modulo a fixed odd prime power are explicitly constructed under the condition that their cardinalities do not exceed an arbitrarily small positive power of the modulus.KEY WORDS: regular sets modulo a prime number, Waxing problem, additive congruences.In [I] the question was raised as to whether there exist regular sets modulo a given number m whose cardinalities do not exceed m ~ , where 0 < e < 1, m _> rot(e), and, for m = pN with a fixed odd prime p, such sets were constructed explicitly. The question resulted from the analysis of the Waxing problem undertaken by the author in [2][3][4][5].Suppose that m is a positive integer, m _> ml > 0, Em is a complete residue system modulo m, A C Era, and IIAII is the cardinality of A. The regular sets A in this theorem consist of the modulo m residues of the numbers z", z = 1, 2,..., [m~], (x, m) = 1, where n is an arbitrary prime from the interval (32e -2 , 64e-2].In a more general setting, a similar problem was considered by Nathanson in [6], where the history of the problem (the Rohrbach problem for finite groups) is described and the following theorem is proved.