@article {Lie07, AUTHOR = {Liesen, J{\"o}rg}, TITLE = {When is the adjoint of a matrix a low degree rational function in the matrix?}, JOURNAL = {SIAM J. Matrix Anal. Appl.}, FJOURNAL = {SIAM Journal on Matrix Analysis and Applications}, VOLUME = {29}, YEAR = {2007}, NUMBER = {4}, PAGES = {1171--1180}, }