@misc{indiciae156e23e5a25c,
  title = {Natural And Artificial Ecosystems},
  author = {Macelroy, Robert D. and Thompson, Brad G. and Tibbitts, Theodore W. and Volk, Tyler},
  year = {1994},
  url = {https://ntrs.nasa.gov/citations/19940000236},
  note = {Source identifier: 19940000236}
}