Some articles/books about functional programming I came across:

• Don Box - Scheme is love
• Sriram Krishnan - Lisp is sin
• Peter Norvig - Paradigms of Artificial Intelligence Programming : Case Studies in Common Lisp
• Hal Abelson, Jerry Sussman and Julie Sussman - Structure and Interpretation of Computer Programs

Probably nothing new to the reader, I just note them so I won't forget them.