Vwani P. Roychowdhury, Farrokh Vatan. On the Existence of Nonadditive Quantum Codes. In Colin P. Williams, editor, Quantum Computing and Quantum Communications, First NASA International Conference, QCQC 98, Palm Springs, California, USA, February 17-20, 1998, Selected Papers. Volume 1509 of Lecture Notes in Computer Science, pages 325-336, Springer, 1998. [doi]