A valuable article on “knockers” — better known in the United States as “tommyknockers” — the diminutive beings whom underground miners have encountered for centuries, by British researcher Sylvia P. Beamon:
UNDERGROUND MYTHOLOGY — WHO, OR WHAT WERE THE KNOCKERS?
Sylvia P. Beamon, M.A.
For presentation at the Symposium on Bohemian Subterranea, Praha (Prague) 22 – 28 August, 1993. Includes: Introduction; Mining Folklore; Cornish Tin Miners; Who were the ‘Knockers’ or the ‘Knackers’?; Scotland and Wales; the Continent and elsewhere; the Czech Republic (with thanks to Vašek Cílek); bibliography & references.