Casgliadau Arlein
Amgueddfa Cymru
Chwilio Uwch
Estimating and Controlling the Heat and Humidity of Coalmine Airflows (report)
N.C.B. Mining Research and Development Establishment Report No.54. 37 pages with green covers.
Nid yw sylwadau ar gael ar hyn o bryd. Ymddiheuriadau am yr anghyfleustra.