Scala Self Types by Gregor Heine, Principal Software Engineer at Gilt
NOTE: Colored pencils/pens may come in handy for color-coding during this lesson! SENTENCE PARTS AND PATTERNS.
The State of Scala
Scala In The Wild
"Scala in Goozy", Alexey Zlobin
Effective Scala: Programming Patterns
Structure your Play application with the cake pattern (and test it)