What is the Holy Bible for your field?
>>7977185
https://www.youtube.com/watch?v=KlPC3O1DVcg
>>7977190
Totally not biased, being from the author of the book.
Of course C is obsolete, that's why all the top CS departments still teach core classes like Operating systems in it.
Google images is my bible. I forget super simple equations all the time, and google images always gives you the proper formula first page. It's good to just glance at fast for remembering the formula.
For example, try to list your inverse trig derivatives.