1.相关链接：http://www.informaworld.com/smpp/content~db=all~content=a914168388~tab=content~order=page
作者：J. Henderson, S.K. Ntouyas, I.K. Purnaras,
标题： Positive solutions for systems of nonlinear discrete boundary value problems,
来源：J. Differ. Equat. Appl. 15 (2009)895–912.
2相关链接：http://www.informaworld.com/smpp/content~db=all~content=a776173049~frm=abslink
作者：J. Henderson, P.J.Y. Wong,
标题：Double symmetric solutions for discrete Lidstone boundary value problems,
来源：J. Differ. Equat. Appl. 7 (2001) 811–828.
3 相关链接：http://www.informaworld.com/smpp/content~db=all~content=a713640039
作者：R. Ma, Y.N. Raffoul,
标题：Positive solutions of three-point nonlinear discrete second order boundary value problem,
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4.相关链接：http://www.ams.org/journals/proc/2009-137-03/S0002-9939-08-09626-3/home.html
作者：F.M. Atici, P.W. Eloe,
标题：Initial value problems in discrete fractional calculus,
来源 Proc. Amer. Math. Soc. 137 (3) (2009) 981–989.