Deuteroproject is devoted to exploring the canon of the Christian Scripture. Specifically the portions that became disputed in the 1500s.
Cross references are notes, often in the margins of a Bible, that connect a word, phrase or passage in one book with a word, phrase or passage in another book somewhere else. In modern times they also are found as footnotes
Cross references are generally not showing quotation of an earlier passage by a later writer. Sometimes they do but often they simply show a use of a common phrase or idea from another place. Perhaps a reference to a similar geographic term, theological idea, retelling of a similar story or event.
The cross references here have been found some in margins, some in published lists of references, etc. Each are more fully described when you follow the links above.
St. Vincent Lerins is my patron. I find his
Commonitorium to be an ancient yet modern work.
I wanted to use a protestant translation. I started my study of these books reading protestant translations, because I was very much a protestant then. In the cross references I use a high number of scripture passages. I ran into licensing and permission issues. There are not many protestant translations that include the deuterocanonical books which limited my choices. Both the RSV and the ESV include the deuterocanonical books, both are very good translations, but both have usage restrictions when you use large amounts of passages. The KJV is old enough I am not restricted in its use so it won by default.
I would have preferred the RSV. It reads easier. I think they focused on a more consistent approach to rendering things in the deuterocanonical books and the other books.