1. IOR/L/PS/20/C158B Reference (shelfmark): IOR/L/PS/20/C158B Title: Supplementary list of undertakings, etc, of a confidential nature between the Trucial Chiefs of Oman and the British Government, 1911-1912. [English and Arabic versions] [Calcutta: Govt of India Foreign and Political Dept, 1916] Collection Area: India Office Records and Private Papers Languages: English Date Range: 1916 Extent: i, 18pp