The resources that I have listed are the course.
And about the paid courses, you’re right. To view all the material from frontendmasters you need a monthly suscription of 40 dollars that you can cancel in any moment. Although I stated that this course is affordable compared to other alternatives and mostly based on frontendmasters maybe I have not stated clearly this idea. So sorry for any trouble caused.
Lastly I remember you that in the post I said that we’ll only rewrite part of the libraries. About your concerns if you would be able to rewrite some of the functions:
If you really want to do it on your own without the guidance provided by the courses, I recommend you to learn from these micro frameworks: http://microjs.com/
Also the “Annotated Source” from the underscore library is a goldmine