Worcester, P. G. (1969). Textbook of geomorphology (2nd ed.). Van Nostrand.
Chicago-čujuhus (17. p.)Worcester, Philip G. Textbook of Geomorphology. 2nd ed. New york: Van Nostrand, 1969.
MLA-čujuhus (9. p.)Worcester, Philip G. Textbook of Geomorphology. 2nd ed. Van Nostrand, 1969.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.