Sponsel, W. (2014). Ernst Christoph Frickhinger 1876-1940: Von Wilfried Sponsel. Steinmeier.
Cita Chicago (17th ed.)Sponsel, Wilfried. Ernst Christoph Frickhinger 1876-1940: Von Wilfried Sponsel. Deiningen: Steinmeier, 2014.
Cita MLA (8th ed.)Sponsel, Wilfried. Ernst Christoph Frickhinger 1876-1940: Von Wilfried Sponsel. Steinmeier, 2014.
Atenció: Aquestes cites poden no estar 100% correctes.