Gaya APA
U.S. National report to International Union of geodesy and geophysics 1987-19990. (1991).
Viena:
American Geophysical Union.
Gaya Chicago
U.S. National report to International Union of geodesy and geophysics 1987-19990.
.
Viena:
American Geophysical Union,
1991.
Text.
Gaya MLA
U.S. National report to International Union of geodesy and geophysics 1987-19990.
.
Viena:
American Geophysical Union,
1991.
Text.
Gaya Turabian
U.S. National report to International Union of geodesy and geophysics 1987-19990.
Viena:
American Geophysical Union,
1991.
Print.