Introduction to research in education 
Ary, Donald. 
 - 6th ed. 
 -  Wadsworth,  2002 
 - xxvi, 582 p. 
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<br/><br/><label>ISBN: </label>0-534-24665-6 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Education -- Research.
<br/><br/><label>Dewey Class. No.: </label>GS 370.72 Ar9i 2002