- A detailed discussion by Derrick Coetzee.
- A short comment at Forty Six and Two
- It is recommended as "wOOt brainfood" here
- I'm not sure how to interpret the comment that it is "a great vulgarization of various concepts". After I asked them, they explained it is a poor translation from French: they mean "a great accessible explanation of various concepts".
- A small discussion on "isKindOf:" in Smalltalk.