Tough, J. (1977). The development of meaning: A study of children's use of language. Allen and Unwin.
Dyfyniad Arddull ChicagoTough, Joan. The Development of Meaning: A Study of Children's Use of Language. London: Allen and Unwin, 1977.
Dyfyniad MLATough, Joan. The Development of Meaning: A Study of Children's Use of Language. Allen and Unwin, 1977.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.