00281nam a2200109Ia 4500008004100000082002400041100001500065245005300080250000900133260002100142300000800163240913s9999||||xx |||||||||||||| ||und||  aGS    303.34  HAJ/P  aT N Hajela 0aPrinciples problems and practice of co operation  aNULL  bNULLaNULLc1992  a702