effects of teaching a foreign language of first language

[Abdulaziz Fageeh]

Hello,

I'm doing a research on the effects of teaching a foreign language on the
first language. Particularly, I would like to investigate the debate between
the opponents and the proponents of teaching a foreign language to children
who are under 12 years of old. If you know some studies and books about this
issue, please let me.

Abdulaziz Fageeh
Indiana University, PA