Clarke, D. Waldo. <br/><br/>
Modern English practice :  exercises in English for foreign students / 
by D. Waldo Clarke and M.D. Munro Mackenzie : key to exercises. 
 - [London] :  Longman,  [1970] 
<br/><br/> First published in 1957. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>English language -- Study and teaching -- Foreign speakers.--English language -- Study and teaching -- Foreign speakers.--English language -- Study and teaching -- Foreign speakers.