↑Sources differ on specific date ranges, which necessarily varied over such a wide geographic expanse. One (Bard, Kathryn A. (1999), ed. Encyclopedia of the Archaeology of Ancient Egypt. London, Routledge, pg 863) gives "9000–5000 BP," or 7000–3000 BCE, for the duration of the subpluvial. Another (Wilkinson, Toby A. H. (1999), Early Dynastic Egypt. London, Routledge, pg 372) places the end of the subpluvial c. 3300 BCE.