BUTLER, G. W. 1990. The 21st Century in Space: Advances in the Astronautical Sciences. Volume 70. 1. vyd. San Diego: American Astronautical Society.
APA (7th ed.) CitationButler, G. W. (1990). The 21st Century in Space: Advances in the Astronautical Sciences. Volume 70 (1. vyd.). American Astronautical Society.
Chicago Style (17th ed.) CitationButler, George W. The 21st Century in Space: Advances in the Astronautical Sciences. Volume 70. 1. vyd. San Diego: American Astronautical Society, 1990.
MLA (9th ed.) CitationButler, George W. The 21st Century in Space: Advances in the Astronautical Sciences. Volume 70. 1. vyd. American Astronautical Society, 1990.
Warning: These citations may not always be 100% accurate.
