@misc{indiciae2b009630f2ab,
  title = {State-variable models of structures having rigid-body modes},
  author = {Craig, Roy R., Jr. and Su, Tsu-Jeng and Ni, Zhenhua},
  year = {1990},
  url = {https://ntrs.nasa.gov/citations/19910034414},
  note = {Source identifier: 19910034414}
}