Bueno-Villaverde, A., V. . Steffen, and C. Van Vooren. “CASE STUDY ON SOCIAL-CULTURAL AND LEADERSHIP FACTORS AFFECTING THE TEACHING OF ADDITIONAL LANGUAGES IN IB INTERNATIONAL SCHOOLS”. Journal of Supranational Policies of Education (JoSPoE), no. 12, Dec. 2020, pp. 26-43, doi:10.15366/jospoe2020.12.002.