WASET
	@article{(Open Science Index):https://publications.waset.org/pdf/15619,
	  title     = {Positive Periodic Solutions in a Discrete Competitive System with the Effect of Toxic Substances},
	  author    = {Changjin Xu and  Qianhong Zhang},
	  country	= {},
	  institution	= {},
	  abstract     = {In this paper, a delayed competitive system with the effect of toxic substances is investigated. With the aid of differential equations with piecewise constant arguments, a discrete analogue of continuous non-autonomous delayed competitive system with the effect of toxic substances is proposed. By using Gaines and Mawhin,s continuation theorem of coincidence degree theory, a easily verifiable sufficient condition for the existence of positive solutions of difference equations is obtained.
},
	    journal   = {International Journal of Mathematical and Computational Sciences},
	  volume    = {5},
	  number    = {4},
	  year      = {2011},
	  pages     = {649 - 653},
	  ee        = {https://publications.waset.org/pdf/15619},
	  url   	= {https://publications.waset.org/vol/52},
	  bibsource = {https://publications.waset.org/},
	  issn  	= {eISSN: 1307-6892},
	  publisher = {World Academy of Science, Engineering and Technology},
	  index 	= {Open Science Index 52, 2011},
	}