Hayes. Soils, Climate and Society. University Press of Colorado.
Chicago-čujuhus (17. p.)Hayes. Soils, Climate and Society. University Press of Colorado.
MLA-čujuhus (9. p.)Hayes. Soils, Climate and Society. University Press of Colorado.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.