Roop, P., & Roop, C. (2007). River roads west: America's first highways. Calkins Creek.
Cita Chicago Style (17a ed.)Roop, Peter, y Connie Roop. River Roads West: America's First Highways. Honesdale, Pa.: Calkins Creek, 2007.
Cita MLA (8a ed.)Roop, Peter, y Connie Roop. River Roads West: America's First Highways. Calkins Creek, 2007.
Precaución: Estas citas no son 100% exactas.