1. Gryazina EN, Polyak BT, Tremba AA (2008) D-decomposition technique state-of-the-art. Automa Remote Control 69(12): 1991–2026
2. Pontryagin LS (1942) On the zeros of some elementary transcendental functions. Izv Akad Nauk SSSR, Ser Mat 6:115–134 (In Russian). English translation (1955) in Am Math Soc Transl (2) 1:95–110
3. Neimark JuI (1949) D-subdivision and spaces of quasi-polynomials. Prikl Mat Mech 13:349–380 (In Russian)
4. El’Sgol’ts LE, Norkin SB (1973) Introduction to the theory and application of differential equations with deviating arguments. Academic Press, New York
5. Stépán G (1989) Retarded dynamical systems: stability and characteristic function. Wiley, New York