@article{701440,
     title = {Integral geometry for complexes of rational curves},
     booktitle = {Proceedings of the Winter School "Geometry and Physics"},
     series = {GDML\_Books},
     publisher = {Circolo Matematico di Palermo},
     address = {Palermo},
     year = {1989},
     pages = {[195]-207},
     mrnumber = {MR1009572},
     zbl = {0679.53061},
     url = {http://dml.mathdoc.fr/item/701440}
}

Gindikin, S. G. Integral geometry for complexes of rational curves, dans Proceedings of the Winter School "Geometry and Physics", GDML_Books,  (1989), pp. [195]-207. http://gdmltest.u-ga.fr/item/701440/