As someone that used to play it. This is an excellent book: The Modernized Colle-Zukertort Attack – second revised & extended edition – Milos Pavlovic
He claimed at another thread that he doesn't read books, and prefers to be graduated by the Holy Spirit.
Incorrect. What I have said is that I do not study chess books. But i love to read them. As for the Holy Spirit you are 110% correct!
Are you the same person with @Josh11live ?
Here is another Colle Koltanowski 9.b4 Blitz over on Lichess in the Anonymous section (my last one I'll be posting .. these games are not model games, just want to show the OP what 9. b4 is all about. For me ... It makes the Colle-Koltanowski playable again