“These included the Deuterocanonicals which are quoted frequently in the New Testament, but were rejected by Protestantism.”
Really? Where does it say, “It is written...” followed by a quote from the Apocrypha?
Unless you can demonstrate to me that every Old Testament reference in the New Testament is prefaced by "It is written" it sounds like busy work. Unless you have actually read the Deuterocanonicals (Tobit, Judith, Wisdom, Sirach (or Ecclesiasticus), Baruch, 1 Maccabees, and 2 Maccabees) and I have met very few Protestants who have, you would have to take my word for it or do your own Google searches.