Hinojo Lucena, Francisco Javier, Inmaculada Aznar Díaz, María Pilar Cáceres Reche, and José María Romero Rodríguez. “A Tour of Open Universities Through Literature: A Bibliometric Analysis”. The International Review of Research in Open and Distributed Learning 20, no. 4 (February 22, 2019). Accessed October 23, 2021. http://www.irrodl.org/index.php/irrodl/article/view/4079.