McDougald, J. S., and D. Pissarello. “Content and Language Integrated Learning: In-Service Teachers’ Knowledge and Perceptions Before and After a Professional Development Program”. Íkala, Revista De Lenguaje Y Cultura, vol. 25, no. 2, Feb. 2020, pp. 353-72, doi:10.17533/udea.ikala.v25n02a03.