Author,Title,Journal,ISSN,Publisher,Date,Volume,Number,Page,URL,URL(DOI) Higashitani Akihiro,Minkowski sum of polytopes and its normality,Journal of the Mathematical Society of Japan,00255645,The Mathematical Society of Japan,2016,68,3,1147-1159,https://cir.nii.ac.jp/crid/1390001205116077824,https://doi.org/10.2969/jmsj/06831147