APA

Closser, S., Rosenthal, A., Parris, T., Maes, K., Justice, J., Cox, K., Luck, M., Landis, R., Grove, J., Tedoff, P., Venczel, L., Nsubuga, P., Kuzara, J., & Neergheen, V. (2012). Methods for evaluating the impact of vertical programs on health systems: protocol for a study on the impact of the global polio eradication initiative on strengthening routine immunization and primary health care. : BioMed Central Ltd.