1. 'ARABIA. Route Traverse across the RUB' AL KHALI from DHUFAR TO DOHA by BERTRAM THOMAS 1930-31' Date: 1931/1931 Language: English Geographic region: Rubʻ al Khālī
2. 'File 38/15 Oil concessions in Arabia and the Gulf (Muscat)' Date: 1933/1949 Language: English Geographic region: BuraimiSaudi ArabiaRubʻ al KhālīOman
3. PZ 2429/1935 'Count Byron de Prorok: activities in Yemen and Persian Gulf' Date: 1935/1939 Language: English Geographic region: MuscatRubʻ al KhālīYemen