@article{DMPS_2008_28_1_a4,
     author = {Baksalary, Oskar and Trenkler, G\"otz},
     title = {An alternative approach to characterize the commutativity of orthogonal projectors},
     journal = {Discussiones Mathematicae. Probability and Statistics},
     pages = {113--137},
     publisher = {mathdoc},
     volume = {28},
     number = {1},
     year = {2008},
     zbl = {1155.15017},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/DMPS_2008_28_1_a4/}
}