Gaya APA
U.S. National report 1987-1990. ().
[s.l]:
[s.n].
Gaya Chicago
U.S. National report 1987-1990.
.
[s.l]:
[s.n],
.
Text.
Gaya MLA
U.S. National report 1987-1990.
.
[s.l]:
[s.n],
.
Text.
Gaya Turabian
U.S. National report 1987-1990.
[s.l]:
[s.n],
.
Print.