OSSAI, E. N.; FATIREGUN, A. A. Clients’ willingness to pay for immunization services in the urban and rural primary health centers of Enugu state, Nigeria. Journal of Public Health in Africa, [S. l.], v. 6, n. 1, 2015. DOI: 10.4081/jphia.2015.480. Disponível em: https://publichealthinafrica.org/jphia/article/view/480. Acesso em: 30 jan. 2023.