@misc{indiciae22e59da6ad45,
  title = {Efficient single-level solution of hierarchical problems in structural optimization},
  author = {Thareja, Rajiv R. and Haftka, Raphael T.},
  year = {1990},
  url = {https://ntrs.nasa.gov/citations/19900038239},
  note = {Source identifier: 19900038239}
}