They wrote a book a few years ago 'The New York Musicals of Comden and Green' which is probably available in your local library. It not only talks about their shows, but has discussions about their relationship while writing them.
I'd skip Betty Comden's 1996 autobiography 'Off Stage' which is mostly about her non-professional life
'Our whole family shouts. It comes from us livin' so close to the railroad tracks'