Mental hygiene in the nursery school :  report of a joint WHO-UNESCO expert meeting held in Paris : 1951. 

 - Paris :  UNESCO,  1953. 
 - 33 p. 
 - Problems in education ;  9. .
<br/><br/><label>No. de Clasificación Universal Decimal: </label>371.7: 373.2 (100)=20 1953MEN No.9.