1. Amerio, L., and G. Prouse, “Almost-periodic Functions and Functional Equations,” Van Nostrand, New York, 1971.
2. Arendt, A., and C. J. K. Batty,Tauberian theorems and Stability of one-parameter semigroups, Trans. Amer. Math. Soc.306 (1988), 837–852.
3. Basit, B.,Note on a theorem of Levitan for the integral of almost periodic functions, Rend. Inst. di Matem. Univ. Trieste5 (1973), 9–14.
4. Basit, B.,Spectral characterization of abstract functions, Analele stiintifici ale Univ. “Ai.I.Cuza” din Iasi28 (1982), 25–34.
5. Basit, B.,Some problems concerning different types of vector almost periodic functions, Dissertationes Math.338 (1995).