Roy, A. (1876). The coal mines: Containing a description of the various systems of working and ventilating mines, together with a sketch of the principal coal regions of the globe, including statistics of the coal production. Robison, Savage & Co..
Trích dẫn kiểu Chicago (xuất bản lần thứ 7)Roy, Andrew. The Coal Mines: Containing a Description of the Various Systems of Working and Ventilating Mines, Together with a Sketch of the Principal Coal Regions of the Globe, Including Statistics of the Coal Production. Cleveland, O.: Robison, Savage & Co., 1876.
Trích dẫn kiểu MLA (xuất bản lần thứ 8)Roy, Andrew. The Coal Mines: Containing a Description of the Various Systems of Working and Ventilating Mines, Together with a Sketch of the Principal Coal Regions of the Globe, Including Statistics of the Coal Production. Robison, Savage & Co., 1876.