@article{Fricker_2012,
title={Multivariate Gaussian Process Emulators With Nonseparable Covariance Structures},
volume={55},
ISSN={1537-2723},
url={http://dx.doi.org/10.1080/00401706.2012.715835},
DOI={10.1080/00401706.2012.715835},
number={1},
journal={Technometrics},
publisher={Informa UK Limited},
author={Fricker,
Thomas E. and Oakley,
Jeremy E. and Urban,
Nathan M.},
year={2012},
month=aug,
pages={47–56} }