Nuanpan Nangsue, Adjusted Ratio and Regression Type Estimators for Estimation of Population Mean when some Observations are missing. journal = {International Journal of Mathematical and Computational Sciences}, [online]. World Academy of Science, Engineering and Technology. May 2009, vol. 29(5). 334 - 337 [viewed 21 September 2024]. Available from: https://publications.waset.org/pdf/14354.