@Misc{SCI:Pen2021a,
  author =    "M. Penwarden and S. Zhe and A. Narayan and R. M.
              Kirby",
  title =     "Multifidelity Modeling for Physics-Informed Neural
              Networks (PINNs)",
  subtitle =  "arXiv preprint arXiv:2106.13361",
  year =      "2021",
  url =       "http://www.sci.utah.edu/publications/Pen2021a/2106.13361.pdf",
}