New York: HarperPerennial.for foreign language learning in the 21st Century Tabors PO, Dr – One child, two languages: a guide for preschool educators of children learning English as a second language. Baltimore Md 1997
Polome EC and Hill CP – Language in Tanzania. Oxford University Press 1980
Singleton D – Language acquisition and the age factor. Clevedon 1989
Learning and Knowing Mathematics in a Computer-Rich School. Norwood, Journal of Computer-based Instruction 20, 86-94. Pinker, S. (1995).