- http://www.cse.chalmers.se/~rjmh/Papers/whyfp.pdf
 - http://shop.oreilly.com/product/0636920028857.do
 - http://stackoverflow.com/questions/36504/why-functional-lang...
I haven't read it yet.
The book explains the complete language. I consider functional programming more of a (fascinating and important!) meta-topic; worthy even of dedicated books  and beyond the scope of Speaking JS.
I can't recommend this book enough. I'm sure some purists wouldn't put it in the same league as SICP, but I think you might like it.
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