APA-čujuhus (7. p.)
Allen, W. L. National Geographic: Vol. 191, no. 1, January 1997. National Geographic Society.
Chicago-čujuhus (17. p.)
Allen, William L. National Geographic: Vol. 191, No. 1, January 1997. Washington, EUA: National Geographic Society.
MLA-čujuhus (9. p.)
Allen, William L. National Geographic: Vol. 191, No. 1, January 1997. National Geographic Society.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.