Cita APA (7a ed.)
Graves, W. National Geographic: Vol. 182, no. 2, August 1992. National Geographic Society.
Cita estilo Chicago (17a ed.)
Graves, William. National Geographic: Vol. 182, No. 2, August 1992. Washington, EUA: National Geographic Society.
Cita MLA (9a ed.)
Graves, William. National Geographic: Vol. 182, No. 2, August 1992. National Geographic Society.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.