"Atsufumi Honda,Kosuke Naokawa,Kentaro Saji,Masaaki Umehara,Kotaro Yamada","On the existence of four or more curved foldings with common creases and crease patterns",,"Beitr?ge zur Algebra und Geometrie / Contributions to Algebra and Geometry",,,,,2021,Oct.
"Masaaki Umehara,Kotaro Yamada","Hypersurfaces with light-like points in a Lorentzian manifold II",,"Kodai Math. J.",,"Vol. 44","No. 1",,2021,Mar.