APA Style
Encyclopedia Americana, Vol 21 Orley to Photographic Telescope. (1966).
New York:
Americana Corporation.
Chicago Style
Encyclopedia Americana, Vol 21 Orley to Photographic Telescope.
1.
New York:
Americana Corporation,
1966.
Text.
MLA Style
Encyclopedia Americana, Vol 21 Orley to Photographic Telescope.
1.
New York:
Americana Corporation,
1966.
Text.
Turabian Style
Encyclopedia Americana, Vol 21 Orley to Photographic Telescope.
New York:
Americana Corporation,
1966.
Print.