TY  - BOOK
AU  - George D.Butler,
ED  - National Recreation Association, Washington
TI  - The new play areas: their design and equipment 
U1  - 136 
PY  - 1938///
CY  - New York
PB  - A.S. Barnes
KW  - Scientists
KW  - Biography
N1  - Bibilography : p. 228-237
ER  -