R.H.J., -. C. D. Ollier, C. J. Lawrance, P. H. T. Beckett & R. Webster: Terrain Classification and Data Storage. Land Systems of Uganda. Geografisk Tidsskrift, [S. l.], v. 73, 1974. Disponível em: https://tidsskrift.dk/geografisktidsskrift/article/view/45711. Acesso em: 16 dec. 2025.