Columbia subject headings:
Electrooptical devices--Congresses.
Geometrical optics--Congresses.
Lenses--Design and construction--Congresses.
Miniature electronic equipment--Congresses.
Harvard subject headings:
Electrooptical devices--Congresses.
Geometrical optics--Congresses.
Geometrical optics.
Lenses--Design and construction
Lenses--Design and construction--Congresses
Miniature electronic equipment--Congresses
Princeton subject headings:
Geometrical optics.
Lenses--Design and construction.