Sufficient and necessary condition for the permanence of periodic predator-prey system. Cui, Jingan; Song, Xinyu — 2004 International Journal of Mathematics and Mathematical Sciences
Permanence in logistic and Lotka-Volterra systems with dispersal and time delays. Cui, Jingan; Guo, Mingna — 2005 Electronic Journal of Differential Equations (EJDE) [electronic only]