Cyfyngwch eich canlyniadau yn ôl:
- Pob un
- Pit-wood., 1 canlyniadau
- Coal -- Research., 1 canlyniadau
- Work environment -- Wales., 1 canlyniadau
- Wages -- Coal miners -- Wales, South., 1 canlyniadau
- Coal mines and mining -- Safety measures -- Wales, South., 1 canlyniadau
- Coal miners -- Diseases -- Wales, South., 1 canlyniadau
- Mining schools and education -- Wales, South., 1 canlyniadau
- Coal miners -- Pensions -- Great Britain., 1 canlyniadau
