John W, Wright and W. A Young, Marysville, Chapter X -- Towns and Villages, History of Marion County, Volume I, S. J. Clarke, Chicago, 1915; pages 172-173.
John W, Wright and W. A Young, Liberty Township, Chapter VI -- Township History, History of Marion County, Volume I, S. J. Clarke, Chicago, 1915; page 114.
John W, Wright and W. A Young, Coal Mining, Chapter XIV -- Finance and Industry, History of Marion County, Volume I, S. J. Clarke, Chicago, 1915; page 254.
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James H. Lees, History of Coal Mining in Iowa, Chapter III of Annual Report, 1908, Iowa Geological Survey, 1909, pages 561-563
E. C. DeWolfe, Operations of Mammoth Vein Coal Co., Bussey, Iowa., The Black Diamond, Vol. 37, No. 5 (Aug. 4, 1906), page 28. Note, Everist was consistently misspelled Everts in this article, but all other sources confirm the spelling Everist.