Elements of number theory - Vinogradov, I. M. (Ivan Matveevich), 1891-1983. (Mineola, New York : Dover Publications, Inc., 2016)
Chapter I- Divisibility Theory (Page-1),Chapter II- Important Number-Theoretical Functions (Page-21),Chapter III- Congruences (Page-41),Chapter IV- Congruences in One Unknown (Page-59),Chapter V- Congruences of Second Degree (Page-79), Chapter VI- Primitive Roots and Indices (Page-105).
Keywords: Number theory