Gaya APA
Pearl, R, M.
(1969).
1001 questions answered about earth science
(
1969)
.
:
New York : Dodd, Mead & Co.,.
Gaya MLA
Pearl, Richard, M.
"1001 questions answered about earth science".
1969
:
New York : Dodd, Mead & Co.,,
1969.
Text.