On the Bohr transform of almost-periodic solutions for some differential equations in abstract spaces. Zaidman, Samuel — 2001 International Journal of Mathematics and Mathematical Sciences
Existence of almost-periodic ultra-weak solutions to the equation u ' ( t ) = a ( t ) A u ( t ) + f ( t ) in Hilbert spaces Samuel Zaidman — 1989 Rendiconti del Seminario Matematico della Università di Padova