References
- Uspensky , J. V. and Heaslet , M. A. 1939 . Elementary Number Theory , McGraw‐Hill .
- Dean , R. A. 1966 . Elements of Abstract Algebra , John Wiley .
- Berman , G. and Fryer , K. D. 1972 . Introduction to Combinatorics , New York : Academic Press .
- Andrews , G. E. 1971 . Number Theory , W. B. Saunders .