Lessenberry, D. D. (1942). 20th century typewriting (4th ed.). South-western Pub. Co..
Chicagoスタイル(17版)引用形式Lessenberry, D. D. 20th Century Typewriting. 4th ed. Cincinnati : New York [etc.]: South-western Pub. Co., 1942.
MLA(8版)引用形式Lessenberry, D. D. 20th Century Typewriting. 4th ed. South-western Pub. Co., 1942.
警告: この引用は必ずしも正確ではありません.