Pretty soon I will be finishing up Understanding Machine Learning: From Theory to Algorithms by Shai Ben-David and Shai Shalev-Shwartz. I absolutely love the subject and want to learn more, the only issue is I'm having trouble finding a book that could come after this. Ultimately, my goal is to read papers in JMLR's COLT.
Is there a book similar to "Understanding Machine Learning: From Theory to Algorithms" that would progress my knowledge further and would go well after reading UML?
Is there any other materials (not a book) that could allow me to learn more or prepare me for reading a journal like the one mentioned above?
(Also, taking courses in this is not really an option, so this will be for self-study).
(Note that I have also asked this question here on TCS SE, but it was recommended I also ask here.)