1Scovel T. A Time to Speak: A Psycholinguistic Inquiry into the Critical Period for Human Speech. New York:Newbury House/Harper & Row. 1988.
2Penfield W, Roberts L. Speech and Brain-mechanisms[M]. Princeton N. J: Princeton University Press, 1959.
3Lenneberg E. Biological Foundations of Lauguage. NewYork:Wiley. 1967.
4Lamendella J. General Principles of Neurofunctional Organization and Their Manifestations in Primary and Non-primary Language Acquisition [J].Language Learning, 1977, 27,155--196.
5Nikolov M. Issues in Research into Early Foreign Language Programs [A].J Moon, M Nikolov (eds). Research into Teaching English to Young Learners: International Perspectives[C]. Pecs, University of Pecs. 2000.21--48.
6Rixon R. English and Other Languages for Younger Children: Practice and Theory in Rapidly Changing World[J]. Language Teaching,1992, 25(2):73-93.
7Driscoll P. MFL in the Primary School: A Fresh Start[A]. P Driscoll, D Frost (eds). The Teaching of Modern Foreign Languages in the Primary School [C]. London:Routledge, 1999. 9--26.
8Vivet, A ' Sens et role des langues dans le dkveloppement des enfant,s', in Council of Europe, Report on Workshop 17, 1995. Strasbourg: Council of Europe. Driscoll P. 1999.
9Blondin C. , Candelier M. , Edelenbos P. , Johnstone R. ,Kubanek--German A, Taeschner T. Foreign Languages in Primary and Pre-School Education. Context and Outcomes. A Review of Recent Research within the European Union. Covent Garden, London: Centre for Information on Language Teaching and Research, 1998.
10Edelenbos P. Leergangen Voor Engels in het basisonderwijs vergeleken. Dissertation University of Groningen. Groningen: RION, 1990.