Do Out-of-Pocket Payments for Care for Children under 5 Persist Even in a Context of Free Healthcare in Burkina Faso? Evidence from a Cross-Sectional Population-Based Survey oleh Ludovic D. G. Tapsoba, Mimbouré Yara, Meike I. Nakovics, Serge M. A. Somda, Julia Lohmann, Paul J. Robyn, Saidou Hamadou, Hervé Hien, Manuela De Allegri