Bui, L.D., Bui, L.D.T., Won, H. and Yong-Gi, K. 2019. Towards a new open educational resource model using OKMindmap. CTU Journal of Innovation and Sustainable Development . 11, 1 (Mar. 2019), 42-48. DOI:https://doi.org/10.22144/ctu.jen.2019.006.