@misc{indiciae06202e3331ad,
  title = {Nonlinear crack analysis with finite elements},
  author = {Armen, H., Jr. and Saleme, E. and Pifko, A. and Levine, H. S.},
  year = {1973},
  url = {https://ntrs.nasa.gov/citations/19740031135},
  note = {Source identifier: 19740031135}
}