Gareth I. Hargreaves, Nicholas J. Higham. Efficient algorithms for the matrix cosine and sine. Numerical Algorithms, 40(4):383-400, 2005. [doi]
@article{HargreavesH05,
title = {Efficient algorithms for the matrix cosine and sine},
author = {Gareth I. Hargreaves and Nicholas J. Higham},
year = {2005},
doi = {10.1007/s11075-005-8141-0},
url = {http://dx.doi.org/10.1007/s11075-005-8141-0},
researchr = {https://researchr.org/publication/HargreavesH05},
cites = {0},
citedby = {0},
journal = {Numerical Algorithms},
volume = {40},
number = {4},
pages = {383-400},
}