TY  - BOOK
AU  - Whelan,P.M.
AU  - Hodgson,M.J.
TI  - Essential principles of physics 
SN  - 0719545668 (pbk.)
U1  - 530 WHE 
PY  - 1989///, [reprinted 1990]
CY  - {S. l.]
PB  - John Murry, 
KW  - Physics
N1  - Physics for schools; Includes index; Bibliography p.540 - p. 541
ER  -