+* [Real World OCaml](https://realworldocaml.org/v1/en/html/index.html) (510 pp. text from 2013)
+ * recommend reading [Chapters 1-4](https://realworldocaml.org/v1/en/html/a-guided-tour.html) when getting started (Chapter 4 is a bit more advanced)
+ * then [Chapter 6](https://realworldocaml.org/v1/en/html/variants.html) when learning types
+ * then [Chapter 8](https://realworldocaml.org/v1/en/html/imperative-programming-1.html) when learning about mutation (OCaml has what we call *explicit* mutation)