@misc{indiciae363f0a3eafee,
  title = {Ceramic port shields cast in an iron engine head},
  author = {Hakim, Nabil S. and Groeneweg, Mark A.},
  year = {1989},
  url = {https://ntrs.nasa.gov/citations/19900040040},
  note = {Source identifier: 19900040040}
}