International Tunnelling Association. (1981). Advances in Tunnelling Technology and Subsurface Use. Pergamon Press.
Citação do estilo Chicago (17ª ed.)International Tunnelling Association. Advances in Tunnelling Technology and Subsurface Use. Oxford, Inglaterra: Pergamon Press, 1981.
Citação MLA (8ª ed.)International Tunnelling Association. Advances in Tunnelling Technology and Subsurface Use. Pergamon Press, 1981.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.