Oxford University Press · Routledge
| title | ISBN-13 | year of publication |
|---|---|---|
| Land Charters of Northern Ethiopia | 978-0-19-644028-6 | 1967 |
| Periplus of the Erythraean Sea | 978-0-904180-05-3 | 2010 |
| The Historical Geography of Ethiopia from the First Century A.D.to 1704 | 978-0-19-726055-5 | 1989 |
| The Nandi of Kenya | 978-0-415-51125-4 | 2011 |