38639
Biggs, Maurice E., Mead, Judson, Whaley, Joseph Floyd
1953
MM05
Mead, J., Biggs, M. E., and Whaley, J. F., 1953, Map of Indiana showing gravitational intensity: Indiana Geological Survey Miscellaneous Map 05, scale 1:500,000.
Indiana Geological & Water Survey - Miscellaneous Map 05