almost periodic function; Fourier coefficient; Fourier exponent; spectrum of almost periodic function; almost periodic system of differential equations; formal almost periodic solution; almost periodic solution; distance of two spectra; time lag; neutral differential equation
The paper is the extension of the author's previous papers and solves more complicated problems. Almost periodic solutions of a certain type of almost periodic linear or quasilinear systems of neutral differential equations are dealt with.
 Amerio, L., Prouse, G.: Almost Periodic Functions and Functional Equations
. Van Nostrand Reihold Company, New York (1971). MR 0275061
| Zbl 0215.15701
 Fink, A. M.: Almost Periodic Differential Equations
. Lecture Notes in Mathematics, Springer, New York (1978). MR 0460799
 Fischer, A.: Existence of almost periodic solution of systems of linear and quasilinear differential equations with time lag
. Czech. Math. J. 106 (1981), 256-268. MR 0629724
 Fischer, A.: Almost periodic solutions with a prescribed spectrum of systems of linear and quasilinear differential equations with almost periodic coefficients and constant lag (Cauchy integral)
. Math. Bohem. 124 (1999), 351-379. MR 1722873
 Levitan, B. M., Zhikov, V. V.: Almost Periodic Functions and Differential Equations
. Cambridge Univ. Press, Cambridge (1982). MR 0690064
| Zbl 0499.43005
 Shimanov, S. N.: Almost Periodic Functions and Differential Equations with Time Lag. VUZ SSSR, Matematika 4 (1959), Russian.