Cita APA (7a ed.)
Graves, W. National Geographic: Vol. 186, no. 1, July 1994. National Geographic Society.
Cita estilo Chicago (17a ed.)
Graves, William. National Geographic: Vol. 186, No. 1, July 1994. Washington, EUA: National Geographic Society.
Cita MLA (9a ed.)
Graves, William. National Geographic: Vol. 186, No. 1, July 1994. National Geographic Society.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.