READ · BOOK
Boundaries
Henry Cloud and John Townsend
Best for the ownership question, if you can set aside the framing.
The book that put the word into general use, and it carries a strong prescriptive tone that will not suit everybody. Take the part that lasts: the distinction between what is genuinely yours to carry and what you have taken on because nobody else would. That question does more work than any amount of language about limits.