"Recursive Functions of Symbolic Expressions and Their Computation by Machine" <a href="http://dspace.mit.edu/handle/1721.1/6096" rel="nofollow">http://dspace.mit.edu/handle/1721.1/6096</a><p>The lambda papers <a href="http://library.readscheme.org/page1.html" rel="nofollow">http://library.readscheme.org/page1.html</a>