Hardcover Set of 8 science books for kids (generally, ca. 1980s) 1. The Skeleton Inside You, 1989 2. What Makes Day and Night, 1986 3. How We Learned the Earth is Round, 1990 (some minor age stains on pages edges and boards) 4. You Can't Make a Move Without Your Muscles, 1982 (some minor age stains on pages edges and boards) 5. Feel the Wind, 1989 6. Gravity is a Mystery, 1986 7. No Measles, No Mumps for Me, 1980 8. Straight Hair, Curly Hair, 1966