APA

United States, . (19). Requests for research, development and engineering (R, D&E) efforts. [Washington, D.C: .

Chicago

United States, . 19. Requests for research, development and engineering (R, D&E) efforts. [Washington, D.C: .

Harvard

United States, . (19). Requests for research, development and engineering (R, D&E) efforts. [Washington, D.C: .

MLA

United States, . Requests for research, development and engineering (R, D&E) efforts. [Washington, D.C: . 19.