Spector, J. Michael; Ifenthaler, Dirk; Sampson, Demetrios; Yang, Lan (Joy); Mukama, Evode; Warusavitarana, Amali et al. Technology Enhanced Formative Assessment for 21st Century Learning, article, July 2016; (https://digital.library.unt.edu/ark:/67531/metadc919604/m1/1/: accessed June 20, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; .