Clegg, K. E. (1961). Subsurface geology and coal resources of the Pennsylvanian system; Sangamon, Macon, Menard, and parts of Christian and Logan Counties, Illinois. [publisher not identified].
Chicago Style (17th ed.) CitationClegg, Kenneth Edward. Subsurface Geology and Coal Resources of the Pennsylvanian System; Sangamon, Macon, Menard, and Parts of Christian and Logan Counties, Illinois. Urbana: [publisher not identified], 1961.
MLA (9th ed.) CitationClegg, Kenneth Edward. Subsurface Geology and Coal Resources of the Pennsylvanian System; Sangamon, Macon, Menard, and Parts of Christian and Logan Counties, Illinois. [publisher not identified], 1961.
Warning: These citations may not always be 100% accurate.