1. Arndt, Henriette L., Robert Woore (2018). Vocabulary learning from watching YouTube videos and reading blog posts. Language Learning and Technology 22.3: 124–142.
2. CEDEFOP (2014). Terminology of European Education and Training Policy: A Selection of 130 Terms. (2nd ed.). Luxembourg: Publications Office.
3. Council of Europe (2001). Common European Framework of Reference for Languages: Learning, teaching, assessment. Strasbourg: Language Policy Unit.
4. Ellis, Nick C. (2006). Cognitive perspectives on SLA: The associative-cognitive CREED. AILA Review 19.1: 100–121.
5. European Commission (2018). Proposal for a Council Recommendation on Key Competences for Lifelong Learning. Brussels: European Commission.