Casgliadau Arlein
Amgueddfa Cymru
Chwilio Uwch
Summary of Research Work 1957 (booklet)
Content summary - details of the research activities carried out by National Coal Board Scientific Department in 1957. 17 pages in pink covers.
Nid yw sylwadau ar gael ar hyn o bryd. Ymddiheuriadau am yr anghyfleustra.