Davis, C. O. (1914). A guide to methods and observation in history; studies in high school observation. Chicago.
Citazione stile Chigago Style (17a edizione)Davis, Calvin Olin. A Guide to Methods and Observation in History; Studies in High School Observation. New York: Chicago, 1914.
Citatione MLA (9a ed.)Davis, Calvin Olin. A Guide to Methods and Observation in History; Studies in High School Observation. Chicago, 1914.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.