(1981). A glimpse of the past: A tourist's guide to industrial trails, slate quarries, mines, mills. Cardiff: Wales Tourist Board.
Chicago-referens (17:e uppl.)A Glimpse of the Past: A Tourist's Guide to Industrial Trails, Slate Quarries, Mines, Mills. Cardiff: Wales Tourist Board, 1981.
MLA-referens (8:e uppl.)A Glimpse of the Past: A Tourist's Guide to Industrial Trails, Slate Quarries, Mines, Mills. Cardiff: Wales Tourist Board, 1981.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.