Cita APA (7a ed.)

Willers, F. A. (1920). Graphische integration. Gruyter.

Cita Chicago Style (17a ed.)

Willers, Friedrich Adolf. Graphische Integration. Berlin [etc.]: Gruyter, 1920.

Cita MLA (9a ed.)

Willers, Friedrich Adolf. Graphische Integration. Gruyter, 1920.