APA (7th ed.) Citation

Schriftgiesserei und Messinglinienfabrik D. Stempel, Amsterdam Continental Types and Graphic Equipment, & Zapf, H. (1968). Optima: Regular, italic, medium, semi bold, black. D. Stempel AG Typefoundry.

Chicago Style (17th ed.) Citation

Schriftgiesserei und Messinglinienfabrik D. Stempel, Amsterdam Continental Types and Graphic Equipment, and Hermann Zapf. Optima: Regular, Italic, Medium, Semi Bold, Black. Frankfurt am Main: D. Stempel AG Typefoundry, 1968.

MLA (9th ed.) Citation

Schriftgiesserei und Messinglinienfabrik D. Stempel, et al. Optima: Regular, Italic, Medium, Semi Bold, Black. D. Stempel AG Typefoundry, 1968.