1. Azbelev NV, Maksimov VP, Rakhmatullina LF: Introduction to the theory of functional differential equations. In Adv Ser Math Sci Eng. Volume 3. World Federation Publisher Company, Atlanta; 1995.
2. Hakl R, Mukhigulashvili S: On a boundary value problem for n -th order linear functional differential systems. Georgian Math J 2005, 12(2):229–236.
3. Kiguradze I, Půža B: Boundary value problems for systems of linear functional differential equations. In Folia Facul Sci Natur Univ Masar Brun, Mathematica. Volume 12. Masaryk University, Brno; 2003.
4. Tchaplygin SA: New Method of Approximate Integration of Differential Equations. GTTI, Moscow-Leningrad; 1932.
5. Luzin: About method of approximate integration of acad. S A Tchaplygin Uspekhi Mat Nauk 1951, 6(6):3–27. (in Russian)