Isaac, Stephen [et al.].
Handbook in research and evaluation : a collection of principles, methods, and strategies useful in the planning, design, and evaluation of studies in education and the behavioral sciences /
Stephen Isaac and William B. Michael. - 2-nd edition 
. - San Diego  : EDITS Publishers,  1981 
. - 234 p. : tab.  24 cm. 
<br/>К.: Бібліогр. в підрядк. прим. 
<br/><label>  ISBN: </label>0-912736-25-9