@ARTICLE {4168,
author={L. Li and D. Qiu Qiu},
doi={10.1016/j.tcs.2008.08.026},
journal={Theoretical Computer Science},
title={A note on quantum sequential machines},
year={2009},
month={January},
volume={410},
number={26},
pages={2529-2535},
ISSN={0304-3975}
}