Vogel, J. (1925). Otto Greiner: Julius Vogel. Velhagen & Klasing.
Cita Chicago (17th ed.)Vogel, Julius. Otto Greiner: Julius Vogel. Bielefeld [u.a.]: Velhagen & Klasing, 1925.
Cita MLA (8th ed.)Vogel, Julius. Otto Greiner: Julius Vogel. Velhagen & Klasing, 1925.
Atenció: Aquestes cites poden no estar 100% correctes.