Surat na di Toru

a Ida ma New Bible Dictionary, Edisi Patoluhon, na diedit D. R. W. Wood, halaman 245; Theological Dictionary of the New Testament, Jilid VII, halaman 572; The International Standard Bible Encyclopedia, Edisi Revisi, Jilid 1, halaman 825; dohot The Imperial Bible-Dictionary, Jilid II, halaman 84.