Murphy Raymond. Essential English grammar: A self study reference and practice book for elementary students of English with answers. Cambridge University Press.
Chicago Edition CitationMurphy Raymond. Essential English Grammar: A Self Study Reference and Practice Book for Elementary Students of English with Answers. 2: Cambridge University Press.
MLA Edition CitationMurphy Raymond. Essential English Grammar: A Self Study Reference and Practice Book for Elementary Students of English with Answers. Cambridge University Press.
Warning: These citations may not always be 100% accurate.