Ludwig, G. H. (2011). Opening space research: Dreams, technology, and scientific discovery. American Geophysical Union.
芝加哥风格引文Ludwig, George H. Opening Space Research: Dreams, Technology, and Scientific Discovery. Washington, DC: American Geophysical Union, 2011.
MLA引文Ludwig, George H. Opening Space Research: Dreams, Technology, and Scientific Discovery. American Geophysical Union, 2011.
警告：这些引文格式不一定是100％准确.