Bier, J. A. (1993). 1830-1870 western emigrant trails, major trails, cutoffs, and alternates. Oregon-California Trails Assoc..
Cita Chicago Style (17a ed.)Bier, James Allen. 1830-1870 Western Emigrant Trails, Major Trails, Cutoffs, and Alternates. Independence, Mo.: Oregon-California Trails Assoc., 1993.
Cita MLA (8a ed.)Bier, James Allen. 1830-1870 Western Emigrant Trails, Major Trails, Cutoffs, and Alternates. Oregon-California Trails Assoc., 1993.
Precaución: Estas citas no son 100% exactas.