APA

United States, . (1991). Announcement of availability: FAA-S-8081-6A, FAA-T-8080-17, FAA-T-8080-18, and FAA-T-8080-19. [Washington, D.C: .

Chicago

United States, . 1991. Announcement of availability: FAA-S-8081-6A, FAA-T-8080-17, FAA-T-8080-18, and FAA-T-8080-19. [Washington, D.C: .

Harvard

United States, . (1991). Announcement of availability: FAA-S-8081-6A, FAA-T-8080-17, FAA-T-8080-18, and FAA-T-8080-19. [Washington, D.C: .

MLA

United States, . Announcement of availability: FAA-S-8081-6A, FAA-T-8080-17, FAA-T-8080-18, and FAA-T-8080-19. [Washington, D.C: . 1991.