Aufsatz(elektronisch)#12014Correcting for Sampling Problems in PISA and the Improvement in Portuguese Students' PerformanceIn: FEUNL Working Paper Series No. 591Ferro, Adriana; Freitas, Pedro; Nunes, Luis C.; Reis, Ana Balcão; Seabra, CarmoFerro, Adriana; Freitas, Pedro; Nunes, Luis C.; Reis, Ana Balcão; Seabra, CarmoBestellen über Zugriff(Open Access)Bestellen über Subito