@article{701691,
     title = {Dirac operator in contact symplectic parabolic geometry},
     booktitle = {Proceedings of the 21st Winter School "Geometry and Physics"},
     series = {GDML\_Books},
     publisher = {Circolo Matematico di Palermo},
     address = {Palermo},
     year = {2002},
     pages = {[97]-107},
     mrnumber = {MR1972428},
     zbl = {1024.53021},
     url = {http://dml.mathdoc.fr/item/701691}
}

Kadlčáková, Lenka. Dirac operator in contact symplectic parabolic geometry, dans Proceedings of the 21st Winter School "Geometry and Physics", GDML_Books,  (2002), pp. [97]-107. http://gdmltest.u-ga.fr/item/701691/