00334nam a2200157Ia 4500008004100000020000900041035001000050082001400060100001700074245004900091250000600140260000900146300000900155500000600164650000600170210723s9999||||xx |||||||||||||| ||und||  aNULL  a23435  aNULLBSYK  aSykes, Peter 0aGuide book of Mechanism in Organic Chemistry  a-  a-b-  aNULL  a0  a-