http://pec.lib.wvu.edu/record/P126031968Anthracite in the Lehigh region of Pennsylvania, 1820-45.<p> Serial issue. Issued as: Uinited States. National Museum. <em>Bulletin</em>, 252. Also issued as: <em>Contributions from the Museum of History and Technology</em>, paper 72.</p>Hoffman, John Nathan.Anthracite coal--Pennsylvania--Lehigh River Valley.14256