↑David E. Aune, ed., The Blackwell Companion to The New Testament (Malden, MA: Wiley-Blackwell, 2010), 9: "While seven of the letters attributed to Paul are almost universally accepted as authentic (Romans, 1 and 2 Corinthians, Galatians, Philippians, 1 Thessalonians, Philemon), four are just as widely judged to be pseudepigraphical, i.e. written by unknown authors under Paul's name: Ephesians and the Pastorals (1 and 2 Timothy and Titus)."
↑Stephen L. Harris (2001). The New Testament: A Student's Introduction (quarta ed.). Bostoniae: McGraw-Hill. p. 366. ISBN9780767420310.