Family planning and fertility : estimating program effects using cross-sectional data / Claus C. Pörtner; Kathleen Beegle; Luc Christiaensen. Washington, DC : The World Bank, Development Research Group, Poverty and Inequality Team, 2011 ; Halle (Saale) : Universitäts- und Landesbibliothek Sachsen-Anhalt, 2011