Complex sentence: There are indeed pages given for the book reference, but not in the reference itself but next to each footnote, i.e. (2): 231 refers to page 231 of the McCann book.
Split into simpler sentences: There are indeed pages given for the book reference, but not in the reference itself but next to each footnote. It uses the to render (2): 231 refers to page 231 of the McCann book.