Key points are not available for this paper at this time.
Vijay Verma, Christopher Scott, Colm O'Muircheartaigh, Sample Designs and Sampling Errors for the World Fertility Survey, Journal of the Royal Statistical Society. Series A (General), Vol. 143, No. 4 (1980), pp. 431-473
Verma et al. (Tue,) studied this question.