@article{BMMS_2004_27_1_a8,
     author = {L.N. Sahoo and S.C. Senapati and M. Dalabehera},
     title = {On {Two} {Methods} of {Unbiased} {Estimation} in {Two-Phase} {Sampling
}                        {Using} {Two} {Auxiliary} {Variables}},
     journal = {Bulletin of the Malaysian Mathematical Society},
     year = {2004},
     volume = {27},
     number = {1},
     url = {http://geodesic.mathdoc.fr/item/BMMS_2004_27_1_a8/}
}