Editionen in
HGV 35623

P. Oxy. 18

On the letter writer, Theon, and concerning the date: end of 4th / beginning of 5th century AD, L. Blumell, Archiv 54 (2008) 219-223.
Nd. J. O’Callaghan, Cart.Crist. Nr. 53 = CPL 270.
4-5
σωτῆρι μω (l. μου), E. P. Wegener.