00405nam a2200097Ia 4500008004100000082002600041100003300067245015300100260004600253300000800299140113s9999    xx            000 0 und d  a378:331(047)(73)   L1  aNational Academy of Sciences  aMobility of Ph.D's before and after the doctorate with associated with economic & educational characteristics of states(Career Patterns Report No.3)  a1971bNational Academy of SciencecU.S.A.  a200