Add references and clean up parts 1 and 2

part2/README.md

@@ -15,3 +15,9 @@ to fail; in that case, just run `elm package install` again.)
 ```bash
 elm live Main.elm --open -- --output=elm.js
 ```
+
+## References
+
+* [Type Annotation syntax reference](http://elm-lang.org/docs/syntax#type-annotations)
+* [`type alias` syntax reference](http://elm-lang.org/docs/syntax#type-aliases)
+* [`List.map` documentation](http://package.elm-lang.org/packages/elm-lang/core/3.0.0/List#map)