Author,Title,Edition,Publisher,Year,Series,Number,ISBN,ISSN,URL
"Geest, T. van der and Gerstel, Rudie and Appel, René and Tervoort, Bernard Th. M.",The Child's communicative competence : language capacity in three groups of children from different social classes,,Mouton,1973,Janua linguarum,,,,https://cir.nii.ac.jp/crid/1130282269396096896