00707nam0-22002651i-450-990003120490403321000312049FED01000312049(Aleph)000312049FED0100031204920000920d1991----km-y0itay50------baitaITLongitudinal ResearchScott Menard.Newbury ParkSage1991Quantitative applications in the social sciences76Menard,ScottITUNINARICAUNIMARCBK99000312049040332110810 SAG11490SESSESLongitudinal Research461548UNINAING01