TY  - BOOK
AU  - Powell,Leonard Sutherland
TI  - A guide to the use of visual aids,
SN  - 85171016
U1  - 371.33/5 POW 
PY  - 1968///
CY  - London
PB  - British Association for Commercial and Industrial Education
N1  - Bibliography: p. 39-40
ER  -