TY  - BOOK
AU  - Welford,W.T.
TI  - Geometrical optics: optical instrumentation 
T2  - Undergraduate textbooks in physics
U1  - 535.32 23
PY  - 1962///
CY  - Amsterdam
PB  - North-Holland
KW  - Optics, Geometrical
N1  - Includes bibliographical references and index
ER  -