@article{10_4064_sm200_2_3,
     author = {Angshuman Bhattacharya and Tirthankar Bhattacharyya},
     title = {Complete {Pick} positivity and unitary invariance},
     journal = {Studia Mathematica},
     pages = {149--162},
     year = {2010},
     volume = {200},
     number = {2},
     doi = {10.4064/sm200-2-3},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/sm200-2-3/}
}