TY  - BOOK
AU  - Welford,W.T.
AU  - Winston,R.(Roland).
TI  - The optics of nonimaging concentrators: : light and solar energy 
SN  - 0127453504
PY  - 1978///
CY  - New York
PB  - Academic Press
KW  - Solar collectors
N1  - Includes index; Bibliography: p.193-194
ER  -