I haven't checked lately, but I think there is relatively little about the shenanigans of P9 at V1 written in English. Hans Kung wrote the forward to an excellent book on the sad history that got translated into English from German, but that book was not the author's primary work on the topic. The primary work is still only available in German.

I nurse the fond but faint hope that one day in a century or two, V1 might be recognized as illegitimate on the premise that that council was not "free." The freedom of a council is a moving concept through the millennia. One expert on the councils compares V1 relative freedom with that of Trent, and V1 just doesn't measure up.