1. The nonexistence of certain finite projective planes;Bruck, R. H.;Canad. J. Math.,1949
2. On simple difference sets;Evans, T. A.;Sankhy\={a},1951
3. A property of biquadratic residues;Chowla, S.;Proc. Nat. Acad. Sci. India Sect. A,1944
4. On difference sets;Chowla, S.;Proc. Nat. Acad. Sci. U.S.A.,1949
5. Combinatorial problems;Chowla, S.;Canad. J. Math.,1950