@article{10_4153_CJM_2000_023_2,
     author = {Gannon, Terry},
     title = {The {Level} 2 and 3 {Modular} {Invariants} for the {Orthogonal} {Algebras}},
     journal = {Canadian journal of mathematics},
     pages = {503--521},
     year = {2000},
     volume = {52},
     number = {3},
     doi = {10.4153/CJM-2000-023-2},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-2000-023-2/}
}