SPEECE, M. Rural marketing constraints in South Kordofan, Sudan. ERDKUNDE, [S. l.], v. 44, n. 3, p. 209–219, 1990. DOI: 10.3112/erdkunde.1990.03.05. Disponível em: https://www.erdkunde.uni-bonn.de/article/view/2213. Acesso em: 10 jun. 2025.