Subject
- First World War (1914-1918)2
- Law enforcement2
- Concessions1
- Imperialism1
- Married women1
- Military administration1
- Military affairs1
- Mining1
- Missionaries1
- Oilfields1
- Passports1
- Petroleum industry1
- Political intelligence1
- Postal services1
- Railway construction1
- Rebellions1
- Revolutions1
- Roads1
- Soldiers1
- Telecommunications networks1