Oberholtzer, E. P. (1900). The referendum in America: Together with some chapters on the history of the initiative and other phases of popular government in the United States. C. Scribner's Sons.

Oberholtzer, Ellis Paxson. The Referendum in America: Together with Some Chapters on the History of the Initiative and Other Phases of Popular Government in the United States. New York: C. Scribner's Sons, 1900.

Oberholtzer, Ellis Paxson. The Referendum in America: Together with Some Chapters on the History of the Initiative and Other Phases of Popular Government in the United States. C. Scribner's Sons, 1900.