Gaya APA

Ptak, R. (1992). The Northern trade route to the spice Islands: South ChinaSea - Sulu Zone - North Moluccas, (14th to early 16thcentury). . : .

Gaya MLA

Ptak, Roderich. "The Northern trade route to the spice Islands: South ChinaSea - Sulu Zone - North Moluccas, (14th to early 16thcentury). ". : , 1992. Majalah.