000 00266nam a2200109Ia 4500
082 _a503
_bKEI
100 _aKEITH, Bill Mac
245 _aWorld of science: Technology of change
260 _aNew Delhi
_bS. Chand and Company
_c1999
300 _a124p.
650 _aPhysics
999 _c2590
_d2590