Wazewski's Topological Method for Caratheodory Systems. - P. K. Palamides; Y. G. Sficas; V. A. Staikos (Math. Syst. Theory, 1984)

Asymptotic behavior of the oscillatory solutions to first order non-autonomous linear neutral delay differential equations of unstable type. - Christos G. Philos; I. K. Purnaras; Y. G. Sficas (Math. Comput. Model., 2007)