@misc{indiciae61670387fa04,
  title = {SIGMA: A Knowledge-Based Simulation Tool Applied to Ecosystem Modeling},
  author = {Dungan, Jennifer L. and Keller, Richard and Lawless, James G.},
  year = {1994},
  url = {https://ntrs.nasa.gov/citations/20010060338},
  note = {Source identifier: 20010060338}
}