HarrisP. (1977) ‘Effect of clustering on costs and sampling errors of random samples’, Journal of the Market Research Society, 19, 3, pp. 112–122.
6.
Journal of the Market Research Society, 25, 1.
7.
KishL. (1965) Survey Sampling.New York: Wiley.
8.
RasbashJ., BrowneW., GoldsteinH., YangM., PlewisI., HealyM., WoodhouseG., DraperD., LangfordI., LewisT. (2000) A Users Guide to ML-wiN.University of London.
9.
TippingS., & PickeringP. (2004) Impact of the geographical size of clusters on the precision of survey estimates. Survey Methods Newsletter, 23, Winter.