Ngonyo, M., and C. Oywer. “A Study of the Evolution and Growth of Public Relations Practice in Kenya”. International Journal of Sciences: Basic and Applied Research (IJSBAR), vol. 33, no. 1, Apr. 2017, pp. 1-14, https://gssrr.org/index.php/JournalOfBasicAndApplied/article/view/7131.