TSOP members have found these references to be useful in their work.
They should be available at university or geological research center libraries.
They are not available from TSOP (except for those listed on our Publications page)

Andrews, H.N., Jr., 1951, American coal-ball floras: Botanical Review, v. 17, p. 431-469.

Andrews, H.N., Jr., and S.H. Mamay, 1952, A brief conspectus of American coal ball studies: Palaeobotanist, v. 1, p. 66-72.

Anderson, T.F., M.E. Brownlee, and T.L. Phillips, 1980, A stable isotope study on the origin of permineralized peat zones in the Herrin coal: Journal of Geology, v. 88, p. 713-722.

Baolin, T., W. Shijun, G. Yingting, L. Hongqi, C. Guiren, and Z. Hong, 1996, Flora of Palaeozoic coal balls of China: The Palaeobotanist, v. 45, p. 247-254.

Baxter, R.W., and A.L. Hornbaker, 1965, Pennsylvanian fossil plants from Kansas coal balls: Kansas Geological Survey, a field conference guidebook for the annual meeting of the Geological Society of America and associated societies, 34 p.

Cady, G.H., 1936, The occurrence of coal balls in No. 6 coal bed at Nashville, Illinois: Transactions of the Illinois Academy of Science, v. 29, p. 157-158.

DeMaris, P.J., 2000, Formation and distribution of coal balls in the Herrin coal (Pennsylvanian), Franklin County, Illinois Basin, USA: Journal of the Geological Society, London, v. 157, p. 221-228.

Eggert, D.L., and T.L. Phillips, 1982, Environments of deposition - coal balls, cuticular shale, and gray-shale floras in Fountain and Parke Counties, Indiana: Indiana Geological Survey Special Report 30, 43 p.

Evans, W.D., and D.H. Amos, 1961, An example of the origin of coal balls: Proceedings of the Geologists’ Association, v. 72, p. 445-454.

Galtier, J., 1997, Coal-ball floras of the Namurian-Westphalian of Europe, in P.C. Lyons and E.L. Zodrow, eds., Euramerican Carboniferous paleobotany and coal geology: Review of Palaeobotany and Palynology, v. 95, p. 51-72.

Gerdon, C.J., T.F. Anderson, and T.L. Phillips, 1997, Petrography and geochemistry of North American and European coal balls: Implications for coal-ball origins (abstract): Geological Society of America, Abstracts with Programs, v. 29, no. 4, p. 16.

Graham, R., 1934, Pennsylvanian flora of Illinois as revealed in coal balls. I: Botanical Gazette, v. 95, p. 453-476.

Graham, R., 1935, Pennsylvanian flora of Illinois as revealed in coal balls. II: Botanical Gazette, v. 97, p. 156-168.

Greb, S.F., C.F. Eble, D.R. Chesnut, Jr., T.L. Phillips, and J.C. Hower, 1999, An in situ occurrence of coal balls in the Amburgy coal bed, Pikeville Formation (Duckmantian), central Appalachian basin, USA: Palaios, v. 14, p. 432-450.

Lyons, P.C., M.A. Millay, E.L. Zodrow, A.T. Cross, and K.S. Gillis, 1995, Discovery of permineralized plant fossils (coal balls) in the Bolsovian (ex Westphalian C)(Middle Pennsylvanian, Upper Carboniferous), Stellarton basin, Nova Scotia, Canada: Canadian Journal of Botany, v. 73, p. 1407-1416.

Lyons, P.C., E.L. Zodrow, M.A. Millay, G. Dolby, K.S. Gillis, and A.T. Cross, 1997, Coal-ball floras of Maritime Canada and palynology of the Foord seam: geologic, paleobotanical and paleoecological implications, in P.C. Lyons and E.L. Zodrow, eds., Euramerican Carboniferous paleobotany and coal geology: Review of Palaeobotany and Palynology, v. 95, p. 31-50.

Mamay, S.H., and E.L. Yochelson, 1953, Floral-faunal associations in American coal balls: Science, v. 118, p. 240-241.

Mamay, S.H., 1954, Two new plant genera of Pennsylvanian age from Kansas coal balls: USGS Professional Paper 254-D, p. 81-95.

Mamay, S.H., and E.L. Yochelson, 1962, Occurrence and significance of marine animal remains in American coal balls: U.S. Geological Survey Professional Paper 354-I, p. 193-224.

Phillips, T.L., M.J. Avcin, and D.J. Berggren, 1976, Fossil peat from the Illinois basin - a guide to the study of coal balls of Pennsylvanian age: Illinois State Geological Survey Educational Series 11, 39 p.

Phillips, T.L., A.B. Kunz, and D.J. Mickish, 1977, Paleobotany of permineralized peat (coal balls) from the Herrin (no. 6) coal member of the Illinois basin: Geological Society of America Microform Publication, v. 7, p. 18-49.

Phillips, T.L., 1980, Stratigraphic and geographic occurrences of permineralized coal-swamp plants - Upper Carboniferous of North America and Europe, in D.L. Dilcher and T.N. Taylor, eds., Biostratigraphy of fossil plants, successional and paleoecological analyses: Stroudsburg, Pennsylvania, Dowden, Hutchinson & Ross, Inc., p. 25-92.

Phillips, T.L., and A.T. Cross, 1995, Early and mid-twentieth century coal-ball studies in North America, in P.C. Lyons, E.D. Morey, and R.H. Wagner, eds., Historical perspective of early twentieth century Carboniferous paleobotany in North America: Geological Society of America, Memoir 185, p. 315-339.

Raymond, A., 1988, The paleoecology of a coal-ball deposit from the Middle Pennsylvanian of Iowa dominated by Cordaitalean gymnosperms: Review of Palaeobotany and Palynology, v. 53, p. 233-250.

Reed, F.D., 1926, Flora of an Illinois coal ball: Botanical Gazette, v. 81, p. 460-468.

Schopf, J.M., 1939, Coal balls as an index to the constitution of coal: Transactions of the Illinois State Academy of Science, v. 31, p. 187-189.

Schopf, J.M., 1975, Modes of fossil preservation: Review of Palaeobotany and Palynology, v. 20, p. 27-53.

Scott, A.C., and G. Rex, 1985, The formation and significance of Carboniferous coal balls: Philosophical Transactions of the Royal Society of London, B311, p. 123-137.

Scott, A.C., D.P. Mattey, and R. Howard, 1996, New data on the formation of Carboniferous coal balls: Review of Palaeobotany and Palynology, v. 93, p. 317-331.

Stopes, M.C., and D.M.S. Watson, 1909, On the present distribution and origin of the calcareous concretions in coal seams, known as "coal balls": Philosophical Transactions of the Royal Society of London, v. B200, p. 167-218.

Willard, D.A., 1993, Vegetational patterns in the Springfield coal bed (Middle Pennsylvanian, Illinois basin): comparison of miospore and coal-ball records, in J.C. Cobb and C.B. Cecil, eds., Modern and ancient coal-forming environments: GSA Special Paper 286, p. 139-152.

Willard, D.A., T.L. Phillips, A.D. Lesnikowska, and W.A. DiMichele, 2007, Paleoecology of the Late Pennsylvanian-age Calhoun coal bed and implications for long-term dynamics of wetland ecosystems: International Journal of Coal Geology, v. 69, p. 21-54.

Winston, R.B., 1986, Characteristic features and compaction of plant tissues traced from permineralized peat to coal in Pennsylvanian coals (Desmoinesian) from the Illinois basin: International Journal of Coal Geology, v. 6, p. 21-41.