@article{oai:tsukuba.repo.nii.ac.jp:00015893,
 author = {Shibata, Yoshihiro},
 issue = {1},
 journal = {Tsukuba Journal of Mathematics},
 month = {Jun},
 pages = {149--209},
 title = {On the Neumann problem for some linear hyperbolic systems of second order},
 volume = {12},
 year = {1988}
}