@article{oai:tsukuba.repo.nii.ac.jp:00018690,
 author = {Ancona, Piero D' and 木下, 保 and KINOSHITA, Tamotu and Spagnolo, Sergio},
 issue = {4},
 journal = {Osaka journal of mathematics},
 month = {Dec},
 pages = {921--939},
 title = {On the 2 by 2 weakly hyperbolic systems},
 volume = {45},
 year = {2008},
 yomi = {キノシタ, タモツ}
}