One novel on the list:
Despair by Vladimir NabokovRead about the other doppelgängers on Mullan's list.
Hermann Karlovich, a Russian businessman, tells how, in Prague, he meets a tramp called Felix who looks exactly like him. Hermann suggests a switch of identities - and then murders the gullible Felix for his own life insurance. The perfect crime. Except that the exact resemblance of the two men may be in Hermann's mind only.