TY  - BOOK
AU  - Erdos,Renee F.
ED  - Longmans & Company
ED  - Unesco
TI  - Teaching by correspondence
U1  - 374.4 23
PY  - 1967///.
CY  - London: , Paris
PB  - Longmans, , Unesco
KW  - Correspondence schools and courses
N1  - Includes bibliography: p. 213-214
ER  -