Did the 40 men who wrote the Bible have access to each other's writing so that they could have copied from each other?
Another answer from our community: Many of them did have access to the books of the Bible written prior to theirs. There are many verses in the Bible that quote other Bible books, and they usually say so. For instance, Luke 20:42 "And David himself saith in the book of Psalms, The LORD said unto my Lord, Sit thou on my right hand,"
I can not verify the number 40 for the authors of the Bible, but remember that in this context copying is not the same as plagiarism.
Many scholars say that the Pentateuch was compiled over a period of centuries by sources now known as the Yahwist, the Elohist, the Deuteronomist and the Priestly Source, then redacted by another source known as the Redactor into much the same form as we have today. Scholars can identify the different sources for different sections of the Books of the Pentateuch by the style, regional bias, modernity of Hebrew, and other clues. So, on this theory, each of the succeeding authors had access to the earlier writing.
New Testament scholars have established that the authors of Matthew's Gospel and Luke's Gospel had access to Mark's Gospel, and used it as their main source for information about the life of Jesus. Whenever Matthew and Luke both agree with Mark, the Greek words used are almost identical, something which could not have happened if they were relying on personal memory or even oral traditions. Internal evidence shows that the author of John's Gospel had access to Mark's Gospel and Luke's Gospel, using Luke as his main source for the life of Jesus.