Katimi, E. L. “The Effect of Retarding Chemical Superplasticizers on the Setting Time of Cement Pastes in Kenya: A Case Study of Ready Mix Concrete in Nairobi”. International Journal of Sciences: Basic and Applied Research (IJSBAR), vol. 28, no. 2, July 2016, pp. 184-19, https://gssrr.org/index.php/JournalOfBasicAndApplied/article/view/5881.