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Bulgarische Kohle : Beiträge zur Kenntnis ihrer Geologie und Wirtschaft
Haberfelner, Erich, (1931)
A Report on the coal resources of the Commonwealth of Australia : Prep. by the Coal and Lignite Panels of the Power Survey Sect. Committee
(1955)
Geologische Skizze des Saarbrücker Steinkohlengebirges
Nasse, Rudolph, (1884)
Goal : with 12 maps and 2 diagr.
Ronaldson, James Henry, (1920)