@misc{indiciaef494b98cf8a7,
  title = {PLANS; a finite element program for nonlinear analysis of structures. Volume 2: User's manual},
  author = {Pifko, A. and Armen, H., Jr. and Levy, A. and Levine, H.},
  year = {1977},
  url = {https://ntrs.nasa.gov/citations/19770026591},
  note = {Source identifier: 19770026591}
}