R. B. Eggleton and P. , Erd? os, Two combinatorial problems in group theory, Acta Arith, pp.111-116, 1972.

W. Gao and A. Geroldinger, On the Structure of Zerofree Sequences, Combinatorica, vol.18, issue.4, pp.519-527, 1998.
DOI : 10.1007/s004930050037

J. E. Olson, An addition theorem modulo p, Journal of Combinatorial Theory, vol.5, issue.1, pp.45-52, 1968.
DOI : 10.1016/S0021-9800(68)80027-4
URL : http://doi.org/10.1016/s0021-9800(68)80027-4

J. E. Olson, Sums of sets of group elements, Acta Arith, vol.28, pp.147-156, 1975.