Research on mathematical thinking of young children :  six empirical studies / 
edited by Leslie P. Steffe. 
 - Reston, Virginia :  National Council of Teachers of Mathematics,  [c1975]. 
 - v, 202 p. :  ill. ;  23 cm. 
<br/><br/> Bibliography: p. 192-202. 
<br/><br/><label>LCCN: </label>75-22461 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Mathematics--Study and teaching (Elementary).<br/>Cognition in children.