Engineering Report on the Drilling in the Missoula/Bitterroot Basins of Montana, Appendix A: Geophysical Logs, Hole MB-6, report, 1978; (https://digital.library.unt.edu/ark:/67531/metadc1634553/m1/1/: accessed July 17, 2024), University of North Texas Libraries, UNT Digital Library, digital.library.unt.edu; .