Page "Michael Spivak" Paragraph 2

Spivak has also written The Joy of TeX: A Gourmet Guide to Typesetting With the AMS-TeX Macro Package and The Hitchhiker's Guide to Calculus.

The famous book Morse Theory, by John Milnor, was based on lecture notes by Spivak and Robert Wells.

Spivak's book Calculus on Manifolds ( often referred to as little Spivak ) is also rather infamous as being one of the most difficult undergraduate mathematics textbooks.