"S. Akamine,A. Honda,M. Umehara,K.Yamada","Bernstein-type theorem for zero mean curvature hypersurfaces without time-like points in Lorentz-Minkowski space",,"Bulletin of the Brazilian Mathematical Society, New Series",,,,"  https://doi.org/10.1007/s00574-020-00196-8",2020,Jan.
"Hasegawa Masaru,Honda Atsufumi,Kosuke Naokawa,Masaaki Umehara,Kotaro Yamada","Intrinsic invariants of Cross Caps",,"Selecta Math. New Ser.",,"Vol. 20",,"pp. 769--785",2014,July