Open and distance education theory revisited: implications for the digital era: edited by Insung Jung, Singapore, Springer, 2019, 121 pp., Springer Briefs in Open and Distance Education ISBN 978-981-13-7739-6 44.99 GBP (paperback); ISBN 978-981-13-7740-2 (ebk). (2nd January 2021) - Olcott, Don