How were the Reaching the Poor studies done?
Wagstaff, A., & Waters, H. (2005). How were the Reaching the Poor studies done? In DR. Gwatkin, A. Wagstaff, & AS. Yazbeck (Eds.), Reaching the Poor with Health, Nutrition, and Population Services: What Works, What Doesn't, and Why (pp. 27-46). The World Bank. http://publications.worldbank.org/index.php?main_page=product_info&cPath=0&products_id=21095