Wanjiru, John Kung’u, and Grace Chumba , trans. 2018. “Modified Regression Type Estimators in the Presence of Non-Response in Two Phase Sampling”. International Journal of Scientific Research and Management (IJSRM) 6 (07): ijsrm/v6i7.m01. https://doi.org/10.18535/ijsrm/v6i7.m01.