MUSA, D. L. ., and J. P. M. . DE OLIVEIRA. “SHARING LEARNER INFORMATION THROUGH A WEB SERVICES-BASED LEARNING ARCHITECTURE”. Journal of Web Engineering, vol. 4, no. 3, Feb. 2005, pp. 263-78, https://journals.riverpublishers.com/index.php/JWE/article/view/4283.