@misc{indiciaee42328c7613c,
  title = {Source apportionment of atmospheric trace gases and particulate matter--Comparison of log-ratio and traditional approaches},
  author = {Mark A. Engle and Bernhard Peucker-Ehrenbrink and Josep M. Martin-Fernandez and David P. Krabbenhoft and Paul J. Lamothe and Michael H. Bothner and Ricardo A. Olea and Allan Kolker and Michael T. Tate},
  year = {2011},
  url = {https://pubs.usgs.gov/publication/70207066},
  note = {Source identifier: 70207066}
}