Author,Title,Journal,ISSN,Publisher,Date,Volume,Number,Page,URL,URL(DOI)
Hekimova M.A. and Bainov D.D.,Periodic solutions of autonomous systems of difference and difference-differential equations with a small delay,Mathematics reports,0386832X,Toyama University,1988,11,,21-69,https://cir.nii.ac.jp/crid/1573387451609376256,