@article{10_4064_sm168_3_6,
     author = {Boris Shekhtman and Les{\l}aw Skrzypek},
     title = {Uniqueness of minimal projections onto
 two-dimensional subspaces},
     journal = {Studia Mathematica},
     pages = {273--284},
     publisher = {mathdoc},
     volume = {168},
     number = {3},
     year = {2005},
     doi = {10.4064/sm168-3-6},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/sm168-3-6/}
}