@misc{indiciae183a4e4036b0,
  title = {Change-in-ratio estimators for populations with more than two subclasses},
  author = {Mark S. Udevitz and Kenneth H. Pollock},
  year = {1991},
  doi = {10.2307/2532404},
  url = {https://pubs.usgs.gov/publication/70180936},
  note = {Source identifier: 70180936}
}