@article{05701457, title = {Multiple positive periodic solutions for delay differential system.}, journal = {Discrete Dynamics in Nature and Society}, volume = {2009}, year = {2009}, doi = {10.1155/2009/239209}, zbl = {1201.34106}, language = {en}, url = {http://dml.mathdoc.fr/item/05701457} }
Hao, Zhao-Cai; Xiao, Ti-Jun; Liang, Jin. Multiple positive periodic solutions for delay differential system.. Discrete Dynamics in Nature and Society, Tome 2009 (2009) . doi : 10.1155/2009/239209. http://gdmltest.u-ga.fr/item/05701457/