Cyfyngwch eich canlyniadau yn ôl:
- Pob un
- Labor disputes -- Wales, South., 3 canlyniadau
- Wages -- Coal miners -- Wales, South., 2 canlyniadau
- Coal miners -- Diseases -- Wales, South., 1 canlyniadau
- Coal -- Research -- Wales., 1 canlyniadau
- Coal mines and mining -- Employees -- Wales, South., 1 canlyniadau
- Grievance procedures -- Wales., 1 canlyniadau
- Industrial relations -- Wales., 1 canlyniadau
- Coal mine accidents -- Wales., 1 canlyniadau