Yang, Cheng-Fu’s form (YCF)
Videos:
https://www.youtube.com/watch?v=rROYiqY72T0
first in a series of video clips covering the entire YCF form
Books:
http://www.taijiworld.com/assets/images/Books/Power%20Taiji.pdf
is the start of a series of books, which (in part) also cover the form
Grading Syllabus:
http://www.taijiworld.com/Grading-Syllabus.html