5 canlyniad
Rhestrir y canlyniadau yn ôl perthnasedd.
Cymraeg: twll turio
Saesneg: borehole
Cymraeg: tyllau turio
Saesneg: boreholes
Cymraeg: gosodiad twll turio amser real
Saesneg: real-time borehole installation
Saesneg: The Borehole Sites and Operations Regulations 1995
Saesneg: earth heat exchanger boreholes