@misc{indiciae447ff3540c06,
  title = {Representation of bidirectional ground motions for design spectra in building codes},
  author = {Jonathan P. Stewart and Norman A. Abrahamson and Gail M. Atkinson and Jack W. Beker and David M. Boore and Yousef Bozorgnia and Kenneth W. Campbell and Craig D. Comartin and I.M. Idriss and Marshall Lew and Michael Mehrain and Jack P. Moehle and Farzad Naeim and Thomas A. Sabol},
  year = {2011},
  doi = {10.1193/1.3608001},
  url = {https://pubs.usgs.gov/publication/70041876},
  note = {Source identifier: 70041876}
}