00574cam a2200217 4500 55690052 TxAuBib 19990618120000.0 990618s1987||||||||||||||||||||||||und|u 9780671638351 p 0671638351 p TxAuBib Gardner, Robert. Science in your backyard. J. Messner, 1987. 19990618. Science Experiments. Scientific recreations. Experiments. Nature study.