简·万思那（英语：Jan Vansina）: Oral Tradition as History, 1985, James Currey Publishers, ISBN 0-85255-007-3, 9780852550076; at page 27 and 28, where Vasina defines oral tradition as "verbal messages which are reported statements from the past beyond the present generation" which "specifies that the message must be oral statements spoken, sung or called out on musical instruments only"; "There must be transmission by word of mouth over at least a generation". He points out that "Our definition is a working definition for the use of historians. Sociologists, linguists or scholars of the verbal arts propose their own, which in, e.g., sociology, stresses common knowledge. In linguistics, features that distinguish the language from common dialogue (linguists), and in the verbal arts features of form and content that define art (folklorists)."
Henige, David（英语：David Henige）. "Oral, but Oral What? The Nomenclatures of Orality and Their Implications" Oral Tradition, 3/1-2 (1988): 229-38. p 232; Henige cites Jan Vansina (1985). Oral tradition as history. Madison, Wisconsin: University of Wisconsin Press
