APA (7th ed.) Citation

(1999). Keystones. Verlag Moritz Diesterweg.

Chicago Style (17th ed.) Citation

Keystones. Frankfurt am Main: Verlag Moritz Diesterweg, 1999.

MLA (9th ed.) Citation

Keystones. Verlag Moritz Diesterweg, 1999.

Warning: These citations may not always be 100% accurate.