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@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/} }
I. M. Gel'fand; M. I. Graev; Z. Ya. Shapiro. Integral geometry in projective space. Funkcionalʹnyj analiz i ego priloženiâ, Tome 4 (1970) no. 1, pp. 14-32. http://geodesic.mathdoc.fr/item/FAA_1970_4_1_a2/