Author,Title,Journal,ISSN,Publisher,Date,Volume,Number,Page,URL,URL(DOI) OOTAKI Seiichi,An analysis of the two-dimensional elastic-plastic stress problem using quadratic programming. Second report. The case of adopting the seventh-degree yield function containing the third invariant of the deviatoric stress tensor.,TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series A,03875008,The Japan Society of Mechanical Engineers,1988,54,502,1258-1262,https://cir.nii.ac.jp/crid/1390001204478518912,https://doi.org/10.1299/kikaia.54.1258