Are authors identified by the chapters they contributed to in multi-authors books
It seems so to me. YMMV by the field, but I can't recall reading any books cited like that, except for compilations of essays where the "chapters" are really papers that are functionally distinct from each other.

Presumably you read a lot of works in your field. Go grab 10 books with multiple authors and see if any of them have a capter-by-chapter authorship breakdown.