@ARTICLE{Zyczkowski2013extra1,
title = {Multiaccess quantum communication and product higher rank numerical range},
url = {http://dl.acm.org/citation.cfm?id=2535650&CFID=493299684&CFTOKEN=97537366},
journal = {Quant. Inf. Comp.},
author = {Demianowicz, M. and Horodecki, P. and {\.Z}yczkowski, K.},
month = {jul},
volume = {13},
year = {2013},
pages = {0541-0566},
arxiv = {http://arxiv.org/abs/1209.0119}
}