@misc{indiciae4ec402575c6e,
  title = {Singularity in structural optimization},
  author = {Patnaik, S. N. and Guptill, J. D. and Berke, L.},
  year = {1993},
  url = {https://ntrs.nasa.gov/citations/19930050941},
  note = {Source identifier: 19930050941}
}