The following books are recommended for further reading in the chapter “Why Were Certain Texts Arbitrarily Excluded From The New Testament Canon?” in How Do You Know You’re Not Wrong?: Responding to Objections That Leave Christians Speechless , by Paul Copan.
The Canon of Scripture (F.F. Bruce)
Christ and the Bible (David Wenham)
“The Biblical Canon” by David Dunbar, in Hermeneutics, Authority, and Canon (eds., D.A. Carson and John Woodbridge)