Powers, Robert M. 1942-
Planetary encounters / Robert M. Powers ; original drawings by Helen Zane Jensen. - Harrisburg. Stackpole Books, 1978. - 288p., [4] leaves of plates : ill. (some col.) ;photographs. 25 cm.
Includes index.
Bibliography: p. 283-284.
9780811712705
Planets--Exploration.
Astronautics.
629.43
Planetary encounters / Robert M. Powers ; original drawings by Helen Zane Jensen. - Harrisburg. Stackpole Books, 1978. - 288p., [4] leaves of plates : ill. (some col.) ;photographs. 25 cm.
Includes index.
Bibliography: p. 283-284.
9780811712705
Planets--Exploration.
Astronautics.
629.43