Ask HN: What good introductions to StandardML are there?

I am looking for a good introduction to StandardML. I would like to understand how to make best use of its type system.

Secondary goal is to be able to understand Chris Okasaki's Purely Functional Data Structures book, in which the examples are given in StandardML.

So far I have found:

- https://homepages.inf.ed.ac.uk/mfourman/teaching/mlCourse/

- https://www.cs.cmu.edu/~rwh/isml/book.pdf

- the YouTube playlist of Dan Grossman's Coursera course about programming languages

- some other YouTube videos

What are your recommendations for books about StandardML?