@article{JLT_1992_2_1_a1,
     author = {J. Hilgert},
     title = {Convexity {Properties} of {Grassmannians}},
     journal = {Journal of Lie theory},
     pages = {013--02},
     publisher = {mathdoc},
     volume = {2},
     number = {1},
     year = {1992},
     url = {http://geodesic.mathdoc.fr/item/JLT_1992_2_1_a1/}
}