@misc{indiciae9641b289797d,
  title = {ARC/INFO to grass conversion manual for the upper Mississippi River system project using the Sun Sparc Station 2 and Grass Version 4.0},
  author = {R. G. Waltermire},
  year = {1993},
  url = {https://pubs.usgs.gov/publication/70128784},
  note = {Source identifier: 70128784}
}