The Federal government defines ELLs as "students enrolled in elementary or secondary education, often born outside the U.S. or speaking a language other than English at home, and not having sufficient mastery of English to meet state standards and excel in an English-Language classroom."
Ortiz, A. A., & Yates, J. R. (2008). Enhancing Scientifically-Based Research for Culturally and Linguistically Diverse Learners. Multiple Voices For Ethnically Diverse Exceptional Learners, 11(1), 13-23.
Orozco, C. & Orozco, M. (2001). Children of Immigration. Harvard University Press: Cambridge, MA.
Ana, S. (2004). Tongue-Tied. Rowman & Litchfield: Lanham, MA.