Siegfried van Vriesland: May 2nd, 1886 - December 4th, 1939.
Cita Chicago (17th ed.)Siegfried Van Vriesland: May 2nd, 1886 - December 4th, 1939.
Cita MLA (8th ed.)Siegfried Van Vriesland: May 2nd, 1886 - December 4th, 1939.
Atenció: Aquestes cites poden no estar 100% correctes.