Cita APA (7a ed.)

Wagner, R. (1910). An Theodor Apel. [s.n.].

Cita Chicago Style (17a ed.)

Wagner, Richard. An Theodor Apel. Leipzig: [s.n.], 1910.

Cita MLA (9a ed.)

Wagner, Richard. An Theodor Apel. [s.n.], 1910.