NIEUWOLT, S. Rainfall variability and drought frequencies in East Africa. ERDKUNDE, [S. l.], v. 32, n. 2, p. 81–88, 1978. DOI: 10.3112/erdkunde.1978.02.01. Disponível em: https://www.erdkunde.uni-bonn.de/article/view/1842. Acesso em: 30 apr. 2025.