Gaffney, M. (2006). The pocket idiot's guide to: Extreme sudoku. Alpha Books Publishers.
Chicago Style (17th ed.) CitationGaffney, Matt. The Pocket Idiot's Guide to: Extreme Sudoku. New York: Alpha Books Publishers, 2006.
MLA (9th ed.) CitationGaffney, Matt. The Pocket Idiot's Guide to: Extreme Sudoku. Alpha Books Publishers, 2006.
Warning: These citations may not always be 100% accurate.