Walton, R. Advanced English C.A.E. grammar practice. Longman.
Chicago Style (17th ed.) CitationWalton, Richard. Advanced English C.A.E. Grammar Practice. London: Longman.
MLA (9th ed.) CitationWalton, Richard. Advanced English C.A.E. Grammar Practice. Longman.
Warning: These citations may not always be 100% accurate.