APA ציטוט

Grabau, A. W. (1922). Ordovician fossils of north China. Geological Survey of China.

Chicago Style (17th ed.) Citation

Grabau, Amadeus W. Ordovician Fossils of North China. Peking: Geological Survey of China, 1922.

ציטוט MLA

Grabau, Amadeus W. Ordovician Fossils of North China. Geological Survey of China, 1922.