@misc{indiciae18b8cf6cefae,
  title = {Thermal Characterization of a Direct Gain Solar Thermal Engine},
  author = {Alexander, Reginald A. and Coleman, Hugh W.},
  year = {1998},
  url = {https://ntrs.nasa.gov/citations/19990009080},
  note = {Source identifier: 19990009080}
}