1. Almost Periodic Functions and Functional Equations;Amerio,1971
2. Sobolev Spaces;Adams,1975
3. Stability of the motion in the large;Barbashin;DAN,1952
4. H. Berestycki and P. L. Lions, Nonlinear scalar field equations, preprint.
5. Asymptotic behavior for an almost periodic strongly dissipative wave equation;Biroli;J. Differential Equations,1980