APA
(1991). Proceedings Of The National Academy Of Sciences Of The United States Of America. U. S. A: National Academy Of Science.
Chicago
1991. Proceedings Of The National Academy Of Sciences Of The United States Of America. U. S. A: National Academy Of Science.
Harvard
(1991). Proceedings Of The National Academy Of Sciences Of The United States Of America. U. S. A: National Academy Of Science.
MLA
Proceedings Of The National Academy Of Sciences Of The United States Of America. U. S. A: National Academy Of Science. 1991.