An improved estimator using two auxiliary attributes. - Sachin Malik; Rajesh Singh (Appl. Math. Comput., 2013)

Improved estimation of population variance using information on auxiliary attribute in simple random sampling. - Rajesh Singh; Sachin Malik (Appl. Math. Comput., 2014)

Estimation of population mean using information on auxiliary attribute in two-phase sampling. - Sachin Malik; Rajesh Singh (Appl. Math. Comput., 2015)