1. Strughold H, Harber H, Buettner K, et al. Where does space begin? Functional concepts at the boundaries between atmo-sphere and space. J Aviat Med 1951; 22:342-349.
2. Humble RW, Henry GN, Larsen WJ. Introduction to space pro-pulsion. In: Humble RW, Henry GN, Larsen WJ (eds.), Space Propulsion Analysis and Design. Reston, VA: American Institute of Aeronautics and Astronautics; 1995.
3. Isakowitz SJ, Hopkins JP, Hopkins JB. International Reference Guide to Space Launch Systems. 3rd edn. Reston, VA: American Institute of Aeronautics and Astronautics; 1999.
4. Loftus JP, Teixeira C. Launch systems. In: Larson WJ, Wertz JR (eds.), Space Mission Analysis and Design. 2nd edn. El Segundo, CA: Microcosm, Inc. and Kluwer Academic Publishers; 1992; Chapter 18.
5. Enzell LN. NASA Historical Data Book, Volumes II and III. Washington, DC: Scientific and Technical Information Division, National Aeronautics and Space Administration; 1988.