Coulthard, T. J., Ramirez, J. A., Barton, N., Rogerson, M., & BrĂ¼cher, T. (2013). Were rivers flowing across the Sahara during the last interglacial? Implications for human migration through Africa. PLoS ONE, 8(9), 0-0. https://doi.org/10.1371/journal.pone.0074834