Perturbation theory

Teufel S, Adiabatic perturbation theory in quantum dynamics, LNM 1821 (2003)

Sjostrand J, Lectures on resonances (Lecture Notes, 2002)

Langhoff P W, Epstein S T, Karplus M, Aspects of time-dependent perturbation theory, RMP 44, 602 (1972)

Ciftci H, Hall R L, Saad N, Perturbation theory in a framework of iteration methods, PLA 340, 388 (2005) – only for special U

Watson K M, Multiple scattering by quantum-mechanical systems, PR 105, 1388 (1957)

Feenberg E, A note on perturbation theory, PR 74, 206 (1948)