Uncertain, Coy, And Hard To Please
- New England Free Press, 1970 p233, 246 pages

Understanding Physics
- Hippocrene Books, 1988, 768 pages
- Dorset Press, 1988, 756 pages

Understanding Physics, Volume I
- NAL/Mentor
- NAL/Mentor, 1969
- Walker, 1966
- NAL/Mentor, Apr-69, 240 pages

Understanding Physics, Volume II
- NAL/Mentor, Apr-69, 239 pages
- Walker, 1966, 251 pages
- NAL/Mentor
- NAL/Mentor, 1969

Understanding Physics, Volume III
- Walker, 1966, 269 pages
- NAL/Mentor, 1969, 269 pages
- NAL/Mentor, Apr-69, 256 pages
- NAL/Mentor

Unidentified Flying Objects
- Gareth Stevens, Inc., 1988, 32 pages
- Gareth Stevens, Inc., 1988, 32 pages
- Dell/Yearling, Sep-90, 32 pages

Universe Ahead: Stories of the Future
- Atheneum (Anthologie), 1975 de Sylvia Engdahl & Rick Roberson

Uranus : The Sideways Planet
- Gareth Stevens, Inc., 1988, 32 pages
- Gareth Stevens, Inc., 1988, 32 pages

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