Álvarez-Álvarez, C., L. Sanchez-Ruiz, and J. Montoya-del-Corte. “Proposal of a Questionnaire to Measure the Level of Interaction in the University Classrooms: Version for Teachers, Students and Observers”. WPOM-Working Papers on Operations Management, vol. 10, no. 1, Mar. 2019, pp. 1-28, doi:10.4995/wpom.v10i1.11245.