Lewis, N. (1973). Thirty days to better English. Dolphin Books.
Chicagoスタイル(17版)引用形式Lewis, Norman. Thirty Days to Better English. Garden City, N.Y.: Dolphin Books, 1973.
MLA(8版)引用形式Lewis, Norman. Thirty Days to Better English. Dolphin Books, 1973.
警告: この引用は必ずしも正確ではありません.