00405nam a2200145Ia 450000500170000000800460001703700120006304000200007504100130009508400210010810000200012924500750014930000090022465000260023320250508150817.0008  250505s9999    xx            000 0 eng d  aTextual  aFEDLbengcFEDL  aeng2eng  a371.2, BRIqFEDL  aBriggs Thomas H 0aImproving instruction : Supervision by principals of secondary schools  a587p  aSchool Administration