https://class.coursera.org/progfun-005/lecture https://www.coursera.org/learn/progfun2
http://www.scala-lang.org/api/2.11.8/
http://www.scala-lang.org/documentation http://www.scala-lang.org/files/archive/spec/2.11/ http://docs.scala-lang.org/glossary/ http://docs.scala-lang.org/style/ http://docs.scala-lang.org/tutorials/tour/variances.html http://docs.scala-lang.org/overviews/collections/introduction