Author,Title,Journal,ISSN,Publisher,Date,Volume,Number,Page,URL,URL(DOI) Takahito Kashiwabara and Issei Oikawa and Guanyu Zhou,Penalty method with Crouzeix–Raviart approximation for the Stokes equations under slip boundary condition,ESAIM: Mathematical Modelling and Numerical Analysis,0764-583X,EDP Sciences,2019-05,53,3,869-891,https://cir.nii.ac.jp/crid/1360004233728530688,https://doi.org/10.1051/m2an/2019008