Grabau, A. W. (1922). Ordovician fossils of north China. Geological Survey of China.
Citación estilo ChicagoGrabau, Amadeus W. Ordovician Fossils of North China. Peking: Geological Survey of China, 1922.
Cita MLAGrabau, Amadeus W. Ordovician Fossils of North China. Geological Survey of China, 1922.
Warning: These citations may not always be 100% accurate.