@misc{indiciae813446a296be,
  title = {A first order backscattering model for a forested canopy with a volume-fraction profile},
  author = {Karam, M. A. and Fung, A. K.},
  year = {1989},
  url = {https://ntrs.nasa.gov/citations/19910031365},
  note = {Source identifier: 19910031365}
}