This work coincided with his appointment to the University of Cairo in 1932, where he gave a series of lectures on religion that bore Seligman's influence. After his return to Oxford, he continued his research on Nuer. It was during this period that he first met Meyer Fortes and A. R. Radcliffe-Brown. Evans-Pritchard began developing Radcliffe-Brown's program of structural-functionalism. As a result, his trilogy of works on the Nuer ("The Nuer", "Nuer Religion", and "Kinship and Marriage Among the Nuer") and the volume he coedited entitled "African Political Systems" came to be seen as classics of British social anthropology. Evans-Pritchard's "Witchcraft, Oracles and Magic Among the Azande" is the first major anthropological contribution to the sociology of knowledge through its neutral — some would say "relativist" — stance on the "correctness" of Zande beliefs about causation. His work focused in on a known psychological effect known as psychological attribution. Evans-Pritchard recorded the tendencies of Azandes to blame or attribute witchcraft as the cause of various mis-happenings. The most notable of these issues involved the deaths of eight Azande people due to the collapse of a termite infested door frame. Evans-Pritchard's empirical work in this vein became well-known through philosophy of science and "rationality" debates of the 1960s and 1970s involving Thomas Kuhn and especially Paul Feyerabend.