Subject
- Military intelligence26
- Military affairs24
- Foreign relations20
- Tribes18
- Slave trade15
- Transport infrastructure15
- Expenditure14
- Colonial administration12
- Geography12
- Foreign affairs11
- Internal politics11
- Land10
- Reports10
- Roads10
- Trade (practice)9
- Arms traffic8
- Customs administration8
- International relations8
- Telegraph lines8
- Biographies7