Otaala, Barnabas <br/><br/>
The development of operational thinking in primary school children :  an examination of some aspects of Piaget's theory among the iteso children ofUganda / 
Barnabas Otaala 
 - New York :  Teachers College Press,  1973 
 - ix, 117 p. :  ill. ;  21 cm. 
<br/><br/>Bibliography : p. 91-96. 
<br/><br/><label>LCCN: </label>72-090520 
<br/><br/><label>Subjects--Personal Names: </label><br/>Piaget, Jean, 1896