@article{GDZPPN002035502,
title = {A problem arising in finite population sampling theory.},
journal = {Aequationes mathematicae},
volume = {28},
year = {1985},
pages = {307-312},
zbl = {0584.62010},
url = {http://dml.mathdoc.fr/item/GDZPPN002035502}
}
Liu, Tzen-Ping; Thompson, M.E. A problem arising in finite population sampling theory.. Aequationes mathematicae, Tome 28 (1985) pp. 307-312. http://gdmltest.u-ga.fr/item/GDZPPN002035502/