Bozkurt, Aras, and Olaf Zawacki-Richter. “Trends and Patterns in Distance Education (2014–2019): A Synthesis of Scholarly Publications and a Visualization of the Intellectual Landscape”. The International Review of Research in Open and Distributed Learning, vol. 22, no. 2, Jan. 2021, pp. 19-45, doi:10.19173/irrodl.v22i2.5381.