1. Qualitative methods of mathematical analysis;El'sgol'c;Transl. Math. Monogr. Am. math. Soc.,1964
2. Variational problems with lags;Sabbagh;J. Optim. Theor. Applic.,1969
3. On extrema of functionals with deviating argument;Kamenskii;Soviet Math. Dokl.,1975
4. On a conditional extremum of a functional with deviating argument;Kamenskii;Soviet Math. Dokl.,1977
5. Variational and boundary value problems for differential equations with deviating argument;Kamenskii;Lecture Notes in Mathematics,1979