Wallace, J. G. <br/><br/>
Stages and transition in conceptual development :   an experimental study /  
J. G. Wallace. 
 - Slough :   N.F.E.R.,   1972. 
 - 247 p. :    ill. ;    22 cm. 
<br/><br/>Includes bibliographical references (p. 236-243) and indexes. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Learning, Psychology of--------<br/>Concepts.--------
<br/><br/><label>Dewey Class. No.: </label>155.423