Pellas, Nikolaos. “The Development of a Virtual Learning Platform for Teaching Concurrent Programming Languages in the Secondary Education: The Use of Open Sim and Scratch4OS”. Journal of e-Learning and Knowledge Society 10, no. 1 (January 25, 2014). Accessed April 19, 2024. https://www.je-lks.org/ojs/index.php/Je-LKS_EN/article/view/876.