Tohutoro APA (7th ed.)

Gustavson, C. G. (1955). A preface to history. McGraw-Hill.

Tohutoru Kātū Chicago (17th ed.)

Gustavson, Carl G. A Preface to History. Nueva York: McGraw-Hill, 1955.

Tohutoro MLA (9th ed.)

Gustavson, Carl G. A Preface to History. McGraw-Hill, 1955.