tetrahedron,

tetrahedron-in-the-box & stellated octahedron (also fits in the
tetrahedron letters 27/12/2017 四面体字母物理化学学术论文
tetrahedron (journal) 2017/07/20 四面体有机化学学术论文考研
i - tetrahedron hdu - 6814
tetrahedron (journal) 2017/06/15 四面体有机化学学术论文考研