00254nam a2200109Ia 4500008004100000082001500041100000900056245003000065250000900095260003200104300000800136240913s9999||||xx |||||||||||||| ||und||  a920  SUR/S  aNULL 0aStephen Hawking Vajanagal  aNULL  bGreen booksaThrissurc2018  a136