Parkman , F. (1950). The Oregon trail. The New American Library.
Cita Chicago Style (17a ed.)Parkman , Francis. The Oregon Trail. The New American Library, 1950.
Cita MLA (9a ed.)Parkman , Francis. The Oregon Trail. The New American Library, 1950.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.