Seepter, Kristina. 2014. “Bilingual and Estonian-Speaking Children Studying in the Same Classes: Relation of Academic Achievement to the pupil’s Mental Ability and Classroom Learning Environment”. Eesti Haridusteaduste Ajakiri. Estonian Journal of Education 2 (1):186-216. https://doi.org/10.12697/eha.2014.2.1.08.