Gaya APA
Sagan, Carl, Leonard, Jonathan Norton. (1967).
LIfe Science Library .
Nederland:
Time-Life International.
Gaya Chicago
Sagan, Carl, Leonard, Jonathan Norton.
LIfe Science Library.
Nederland:
Time-Life International,
1967.
Text.
Gaya MLA
Sagan, Carl, Leonard, Jonathan Norton.
LIfe Science Library.
Nederland:
Time-Life International,
1967.
Text.
Gaya Turabian
Sagan, Carl, Leonard, Jonathan Norton.
LIfe Science Library.
Nederland:
Time-Life International,
1967.
Print.