@misc{indiciae481944a44e69, title = {GSDIG; a program to determine latitude/longitude location using a microcomputer (IBM-PC or compatible) and digitizer; program disk}, author = {Gary I. Selner and Cole L. Smith and Richard B. Taylor}, year = {1988}, doi = {10.3133/ofr8814b}, url = {https://pubs.usgs.gov/publication/ofr8814B}, note = {Source identifier: ofr8814B} }