Crowther, J. (1980). Introductory crosswords: For learners of English as a foreign language. Tokyo: Oxford University Press.
Trích dẫn kiểu ChicagoCrowther, Jonathan. Introductory Crosswords: For Learners of English As a Foreign Language. Tokyo: Oxford University Press, 1980.
Trích dẫn MLACrowther, Jonathan. Introductory Crosswords: For Learners of English As a Foreign Language. Tokyo: Oxford University Press, 1980.
Cảnh báo: Các trích dẫn này có thể không phải lúc nào cũng chính xác 100%.