Posthoff Christian : Asymptotic theory of elliptic boundary value problems in singularly perturbed domains. Volume I / Vladimir Maz'ya, Serguei Nazarov, Boris Plamenevskij ; translated from the German by Georg Heinig and Christian Posthoff.
Postlethwait Samuel N : The audio-tutorial approach to learning, through independent study and integrated experiences / by S.N. Postlethwait, J. Novak and H.J. Murray.