Visser, Marieta, Mariette Nel, Juanne de Vries, Erina Klopper, Kabi Olën, Johanette van Coller, and Karmen Nadine Heimes. 2014. “In-Hand Manipulation in Four-and Five-Year-Old Children: Translation, Rotation and Shift Movements”. South African Journal of Occupational Therapy 44 (2): 22-28. https://journals.assaf.org.za/index.php/sajot/article/view/19679.