Based on Jones & Mattingly's Atlas of Roman Britain (ISBN 978-1-84217-06700, 1990, reprinted 2007) — the source is cited in the image legend — regions with AS cemeteries are from p. 317 (early 5th century) and p. 318 (late 5th century); the towns are from p. 310 (all Romano-British, save Canterbury, which is given as possibly Anglo-Saxon); major inland waterways are from p. 199; the degree of Romanisation ("boundaries of acculturation" with levels from "high density" to "low density" in the text) are given on page 151, with the authors citing it as a computer-generated map based on data contained in the standard Ordnance Survey map of Roman Britain.