1. 'Monograph on the Aden Hinterland as touching the States of Dthala, Yafa', Alawi, etc., by Major H F Jacob, late Political Agent, Dthala.' Creator: Author: Harold Fenton Jacob Date: 1908/1908 Language: English Geographic region: DthalaYafa'
2. File 600/1905 Pt 1-3 'Aden Hinterland Affairs' Date: 1904/1915 Language: English Geographic region: YemenDthalaAden