Dyfyniad APA

Lessenberry, D. D., & Crawford, T. J. (1947). 20th century typewriting (4th ed.). South-western Publishing Co..

Dyfyniad Arddull Chicago

Lessenberry, D. D., and T. James Crawford. 20th Century Typewriting. 4th ed. [Cincinnati] : [New York, etc.: South-western Publishing Co., 1947.

Dyfyniad MLA

Lessenberry, D. D., and T. James Crawford. 20th Century Typewriting. 4th ed. South-western Publishing Co., 1947.

Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.