1. BakerC.WrightW. E. (2017). Foundations of bilingual education and bilingualism (6th ed.). Multilingual Matters.
2. Language promotion by European supra-national institutions;H. B.Beardsmore;Bilingual education in the 21st Century: A global perspective,2009
3. BermúdezJ. L. (2020). Cognitive science: An introduction to the science of the mind (3rd ed.). Cambridge UP.
4. Motivation and informal language learning;A.Chik;The handbook of informal language learning,2020
5. Chumak-HorbatschR. (2019). Using linguistically appropriate practice: A guide for teaching in multilingual classrooms. Multilingual Matters.