Huber, R, Hof P, Duarte RO, Moura JJG, Moura I, Liu MY, Legall J, Hille R, Archer M, Romao MJ.  1996.  A structure-based catalytic mechanism for the xanthine oxidase family of molybdenum enzymes. Proceedings of the National Academy of Sciences of the United States of America. 93:8846-8851., Number 17