Gaya APA
Scientific Event Alert Network (SEAN) Buletin Volume 12, No. 7, July 31, 1987. ().
Washington:
Smithsonian Instituion.
Gaya MLA
Scientific Event Alert Network (SEAN) Buletin Volume 12, No. 7, July 31, 1987.
.
Washington:
Smithsonian Instituion,
.
.