Davis, C. O. A Guide to Methods and Observation in History Studies in High School Observation.
Chicago-referens (17:e uppl.)Davis, Calvin Olin. A Guide to Methods and Observation in History Studies in High School Observation.
MLA-referens (9:e uppl.)Davis, Calvin Olin. A Guide to Methods and Observation in History Studies in High School Observation.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.