REFERENCES
- Marc A. Berger, Alexander Felzenbaum, and Aviezri S. Fraenkel, New results for covering systems of residue sets, Bulletin (New Series) of the Amer. Math. Soc., 14 (1986) 121–125.
- R. J. Simpson, Disjoint covering systems of congruences, this Monthly, 94 (1987) 865–868.