1. Properties of the solutions of certain functional differential equations;Fite;Trans. Am. math. Soc.,1921
2. Linear Differential Equations with Retarded Argument;Mishkis,1972
3. Introduction in the Theory of Differential Equations with Deviating Argument;Elsgoltz,1971
4. Theory of Functional-Differential Equations;Hale,1977
5. Ordinary and Delay Differential Equations;Driver,1977