Cita APA (7a ed.)

Hugo, P., Schalk, K., & Barnes, S. (1983). Bibliography of South West African/Namibian Earth Science. Department of Economic Affairs. Geological Survey.

Cita Chicago Style (17a ed.)

Hugo, P.J, K.E.L Schalk, y Sarah-Jane Barnes. Bibliography of South West African/Namibian Earth Science. Windhoek, South West Africa: Department of Economic Affairs. Geological Survey, 1983.

Cita MLA (9a ed.)

Hugo, P.J, et al. Bibliography of South West African/Namibian Earth Science. Department of Economic Affairs. Geological Survey, 1983.