Joubert, Yvonne Trijntje; De Beer, J.J. (Johannes Jacobus), 1947-(Southern African Alliance for Sport Science, Physical Education and Recreation, 2014)
Joubert, Yvonne Trijntje; De Beer, J.J. (Johannes Jacobus), 1947-; De Beer, Hannes, 1947-(Southern African Alliance for Sport Science, Physical Education and Recreation, 2011)
Brand, H.E. (Heinrich Everhardus); Barreiro-Lucas, Judite(Graduate School of Business Leadership and the Department of Business Management, University of South Africa, 2014)