Author,Title,Journal,ISSN,Publisher,Date,Volume,Number,Page,URL,URL(DOI)
GARCIA RONALDO and GUTIERREZ CARLOS and SOTOMAYOR JORGE,Lines of principal curvature around umbilics and Whitney umbrellas,"Tohoku Mathematical Journal, Second Series",0040-8735,"Mathematical Institute, Tohoku University",2000,52,2,163-172,https://cir.nii.ac.jp/crid/1390282680093826176,https://doi.org/10.2748/tmj/1178224605