Omieno, K.K., Oenga, L. and Raburu, D.G. 2013. Usability Evaluation Approach for VLS: A Conceptual Framework. INTERNATIONAL JOURNAL OF COMPUTERS & TECHNOLOGY. 6, 2 (May 2013), 317–320. DOI:https://doi.org/10.24297/ijct.v6i2.3496.