@article{10_4064_sm191_3_8,
     author = {Lajos Moln\'ar and Werner Timmermann},
     title = {A metric on the space of projections
 admitting nice isometries},
     journal = {Studia Mathematica},
     pages = {271--281},
     year = {2009},
     volume = {191},
     number = {3},
     doi = {10.4064/sm191-3-8},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/sm191-3-8/}
}