Dunbar, S. (1915). A history of travel in America: Showing the development of travel and transportation from the crude methods of the canoe and the dog-sled to the highly organized railway systems of the present, together with a narrative of the human experiences and changing social conditions that accompanied this economic conquest of the continent. Indianapolis: Bobbs-Merrill Co..

Dunbar, Seymour. A History of Travel in America: Showing the Development of Travel and Transportation From the Crude Methods of the Canoe and the Dog-sled to the Highly Organized Railway Systems of the Present, Together With a Narrative of the Human Experiences and Changing Social Conditions That Accompanied This Economic Conquest of the Continent. Indianapolis: Bobbs-Merrill Co., 1915.

Dunbar, Seymour. A History of Travel in America: Showing the Development of Travel and Transportation From the Crude Methods of the Canoe and the Dog-sled to the Highly Organized Railway Systems of the Present, Together With a Narrative of the Human Experiences and Changing Social Conditions That Accompanied This Economic Conquest of the Continent. Indianapolis: Bobbs-Merrill Co., 1915.