Author: John McCarthy
Title: Recursive Functions of Symbolic Expressions and Their Computation by Machine, Part I.
Year: 1960
Source: https://web.archive.org/web/20131004232653/http://www-formal.stanford.edu/jmc/recursive.pdf
Source: https://web.archive.org/web/20131006003734/http://www-formal.stanford.edu/jmc/recursive.html
Source: https://dl.acm.org/doi/10.1145/367177.367199