Key points are not available for this paper at this time.
Henri C. Barik, Merrill Swain, Primary-Grade French Immersion in a Unilingual English-Canadian Setting: The Toronto Study through Grade 2, Canadian Journal of Education / Revue canadienne de l'éducation, Vol. 1, No. 1 (1976), pp. 39-58
Barik et al. (Thu,) studied this question.