@article{FAA_1970_4_1_a2,
     author = {I. M. Gel'fand and M. I. Graev and Z. Ya. Shapiro},
     title = {Integral geometry in projective space},
     journal = {Funkcionalʹnyj analiz i ego prilo\v{z}eni\^a},
     pages = {14--32},
     publisher = {mathdoc},
     volume = {4},
     number = {1},
     year = {1970},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/FAA_1970_4_1_a2/}
}