Pre-test geological and geochemical evaluation of the Caprock, St. Peter Sandstone and formation fluids, Yakley Field, Pike County, Illinois, report, March 1, 1983; (https://digital.library.unt.edu/ark:/67531/metadc1212590/m1/149/: accessed July 16, 2024), University of North Texas Libraries, UNT Digital Library, digital.library.unt.edu; .