@misc{indiciae33d9e0fd20d7,
  title = {Hybrids for heavy-lift propulsion - Unsolved problems},
  author = {Ramohalli, Kumar and Yi, Jianwen and Wygle, Brian},
  year = {1992},
  url = {https://ntrs.nasa.gov/citations/19920074453},
  note = {Source identifier: 19920074453}
}