APA (7th ed.) Citation

Fricke, W., Heiland, F., & Oppermann, A. (1920). Geometrie. Westermann.

Chicago Style (17th ed.) Citation

Fricke, Walter, Fritz Heiland, and Albert Oppermann. Geometrie. Braunschweig u.a: Westermann, 1920.

MLA (9th ed.) Citation

Fricke, Walter, et al. Geometrie. Westermann, 1920.