Author,Title,Journal,ISSN,Publisher,Date,Volume,Number,Page,URL,URL(DOI)
Massafumi Yoshino and Todor Gramchev and Petar Popivanov,Critical Gevrey index for hypoellipticity of parabolic operators and Newton polygones,Annali di Matematica Pura ed Applicata,0373-3114,Springer Science and Business Media LLC,1996-12-01,170,,103-131,https://cir.nii.ac.jp/crid/1871428068232779136,https://doi.org/10.1007/bf01758985