Functional Programing in Scala by Paul Chiusano and Rúnar Bjarnason
http://www.manning.com/bjarnason/ (eBook: http://www.manning.com/ebookoffer/)
http://www.manning.com/about/meap.html
https://github.com/fpinscala/fpinscala
http://www.scala-lang.org/api/current/index.html#scala.collection.immutable.List
http://tutorials.jenkov.com/java-util-concurrent/executorservice.html