Forsythe, Gary. A Critical History of Early Rome: From Prehistory to the First Punic War. Berkeley: University of California Press, 2006. Page 309
Kaszynski, William. The American Highway: The History and Culture of Roads in the United States. Jefferson, N.C.: McFarland, 2000. Page 9
Gabriel, Richard A. The Great Armies of Antiquity. Westport, Conn: Praeger, 2002. Page 9.
Bailey, L. H., and Wilhelm Miller. Cyclopedia of American Horticulture, Comprising Suggestions for Cultivation of Horticultural Plants, Descriptions of the Species of Fruits, Vegetables, Flowers, and Ornantal Plants Sold in the United States and Canada, Together with Geographical and Biographical Sketches. New York [etc.]: The Macmillan Co, 1900. Page 320.
Aitken, Thomas. Road Making and Maintenance: A Practical Treatise for Engineers, Surveyors, and Others. London: C. Griffin and Company, Limited, 1900. Page 1 - 5.
