1. Bulmer, M., and Warwick, D. P., eds. 1993. Social research on developing countries: Surveys and censuses in the Third World. London: University College London Press.
2. Casley, D. J., and Lury, D. A. 1981. Data collection in developing countries. London: Oxford University Press.
3. Tourangeau, R., Rips, L. J., and Rasinski, K. 2000. The psychology of survey response. Cambridge, UK: Cambridge University Press.
4. United Nations. 2005. Household surveys in developing and transitional countries. http://unstats.un.org/unsd/Hhsurveys (October 30, 2009).
5. Willis, G. B. 1999. Cognitive interviewing: A “how to” guide. http://appliedresearch.cancer.gov/areas/cognitive/interview.pdf .