REFERENCES
AN INTRODUCTION TO PALEOBOTANY. C. A. Arnold. McGraw-Hill Book Co., New York, 1947, 433 p.
GRUNDY AND WILL COUNTIES. Frank H. Bradley. In Worthen et al., Geology and Paleontology, Geological Survey of Illinois, vol. IV, 1870, p. 190-225.
PALMLIKE PLANTS FROM THE DOLORES FORMATION (TRIASSIC), SOUTHWESTERN COLORADO. Roland W. Brown. United States Geological Survey Professional Paper 274-H, 1956, p. 205-209.
CARBONIFEROUS INSECTS FROM THE VICINITY OF MAZON CREEK, ILLINOIS. F. M. Carpenter. Illinois State Museum Scientific Paper 3, pt. 1, 1943, p. 7-20.
THE LIVING CYCADS. C. J. Chamberlain. University of Chicago Press, Chicago, 1919, 172 p.
GUIDE FOR BEGINNING FOSSIL HUNTERS. Charles Collinson. Illinois State Geological Survey Educational Series 4, 1956, 36 p. (Revised 1959, 40 p.)
HISTORICAL GEOLOGY. Carl O. Dunbar. John Wiley & Sons, Inc., New York, 1949, 576 p.
COLLEGE BOTANY. Harry J. Fuller and Oswald Tippo. Henry Holt & Co., New York, 1954, 993 p.
HANDBUCH DER PALÄOBOTANIK, BD. 1: THALLOPHYTA, BRYOPHYTA, PTERIDOPHYTA. Max Hirmer. R. Oldenbourg, Munich and Berlin, 1927, 708 p.