@article{04210559, title = {Existence of periodic solutions of impulsive differential systems.}, journal = {Journal of Applied Mathematics and Stochastic Analysis}, volume = {4}, year = {1991}, pages = {137-146}, doi = {10.1155/S1048953391000102}, zbl = {0732.34008}, language = {en}, url = {http://dml.mathdoc.fr/item/04210559} }
Erbe, L.H.; Liu, Xinzhi. Existence of periodic solutions of impulsive differential systems.. Journal of Applied Mathematics and Stochastic Analysis, Tome 4 (1991) pp. 137-146. doi : 10.1155/S1048953391000102. http://gdmltest.u-ga.fr/item/04210559/