Nigro, J. C. (1982). Firing an iron ore pelletizing kiln with low-Btu gas from lignite. U.S. Dept. of the Interior, Bureau of Mines.
Lua i Stíl Chicago (17ú heag.)Nigro, John C. Firing an Iron Ore Pelletizing Kiln with Low-Btu Gas from Lignite. [Washington, D.C.]: U.S. Dept. of the Interior, Bureau of Mines, 1982.
Lua MLA (9ú heag.)Nigro, John C. Firing an Iron Ore Pelletizing Kiln with Low-Btu Gas from Lignite. U.S. Dept. of the Interior, Bureau of Mines, 1982.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.