@ARTICLE{Choi2006,
doi = {http://dx.doi.org/10.1016/j.laa.2006.03.019},
title = {{H}igher-rank numerical ranges and compression problems},
url = {http://www.sciencedirect.com/science/article/pii/S0024379506001637},
timestamp = {2013.10.28},
journal = {Linear Algebra and its Applications},
author = {Man-Duen Choi and David W. Kribs and Karol \.Zyczkowski},
volume = {418},
year = {2006},
owner = {lacek},
pages = {828 - 839},
number = {2–3},
keywords = {Hilbert space},
issn = {0024-3795}
}