Introduction to combinatory logic. - J. Roger Hindley; Rasmus Lerdorf; Jonathan P. Seldin (Cambridge University Press, 1972)

PHP pocket reference - web scripting. - Rasmus Lerdorf (O'Reilly, 2000)

Programming PHP - creating dynamic web pages. - Rasmus Lerdorf; Kevin Tatroe (O'Reilly, 2002)

PHP - pocket reference: creating dynamic web pages: covers PHP 4 (2. ed). - Rasmus Lerdorf (O'Reilly, 2002)

Programming PHP - creating dynamic web pages: covers PHP 5 (2. ed.). - Rasmus Lerdorf; Kevin Tatroe; Peter B. MacIntyre (O'Reilly, 2006)