@misc{indiciaee7ce0d2075ab,
  title = {Construction of Covariance Functions with Variable Length Fields},
  author = {Gaspari, Gregory and Cohn, Stephen E. and Guo, Jing and Pawson, Steven},
  year = {2005},
  url = {https://ntrs.nasa.gov/citations/20050156903},
  note = {Source identifier: 20050156903}
}