@Article{puchala11product, author = {Puchała, Z. and Gawron, P. and Miszczak, J.A. and Skowronek, Ł. and Choi, M.-D. and Życzkowski, K.}, title = {Product numerical range in a space with tensor product structure}, doi = {10.1016/j.laa.2010.08.026}, journal = {Linear Algebra Appl.}, volume = {43}, number = {1}, pages = {327-342}, year = {2011}, archivePrefix = {arXiv}, preprint = {1008.3482}, }