Não informado. (1969). Tunnels and Tunnelling. Morgan Grampian.
Style de citation Chicago (17e éd.)Não informado. Tunnels and Tunnelling. London: Morgan Grampian, 1969.
Style de citation MLA (8e éd.)Não informado. Tunnels and Tunnelling. Morgan Grampian, 1969.
Attention : ces citations peuvent ne pas être correctes à 100%.