Beard, Ruth M <br/><br/>
Outline of piagets developmental psychology for students and teachers 

 - London  Routledge and Kegan Paul  1969 
 - xvi, 128 p.;18cm. 
 - Students library of education .
<br/><br/><label>Subjects--Topical Terms: </label><br/>Concrete operations<br/>Developmental psychology<br/>Pre-concephial sub-stage<br/>Sensori - motor period