@misc{indiciaebc63fbedb648,
  title = {Flat-sided rectilinear trough as a solar concentrator - An analytical study},
  author = {Burkhard, D. G. and Strobel, G. L. and Burkhard, D. R.},
  year = {1978},
  url = {https://ntrs.nasa.gov/citations/19780055727},
  note = {Source identifier: 19780055727}
}