Vermeersch, PM., Otte, M., Gilot, E., Paulissen, E., Gijselings, G., & Drappier, D. (1982). Blade Technology in the Egyptian Nile Valley - Some New Evidence. Science, 216(4546), 623-628. https://doi.org/10.1126/science.216.4546.626 (Original work published 1982)