Various. Scientific American Supplement, No. 832, December 12, 1891.
Chicago-čujuhus (17. p.)Various. Scientific American Supplement, No. 832, December 12, 1891.
MLA-čujuhus (9. p.)Various. Scientific American Supplement, No. 832, December 12, 1891.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.