1. N. H. Kemp, D. I. Rosen and H. H. Legner, Laser energy absorption in gases: research problems, orbit-raising and maneuvering propulsion: research status and needs, in AIAA Progress in Astronautics and Aeronautics, (Edited by L. H. Caveny), Vol. 89, p. 73, AIAA, New York.
2. D. I. Rosen, A. N. Pirri, R. F. Weiss, and N. H. Kemp, Repetitively pulsed laser propulsion: needed research, p. 95, Ref. [3].
3. N. H. Kemp and H. H. Legner, Steady (continuous wave) laser propulsion: research areas, p. 109, Ref. [3].