
I don't think I've seen them recommended anywhere (except the Learning to Learn one, which is now available on youtube), maybe they don't fit curricula or not advanced enough or outdated. I just really like his voice, and the way they're soaked with practical experience.
For example, I was able to buy a technical book which retails for $49 on my Kindle for only $8. Not 99 cents, but it still saved me a lot of money.
http://www.amazon.com/Numerical-Methods-Scientific-Computing...