@article{JEMS_2012_14_6_a4,
     author = {Matthias Hammerl and Petr Somberg and Vladim{\'\i}r Sou\v{c}ek and Josef \v{S}ilhan},
     title = {On a new normalization for tractor covariant derivatives},
     journal = {Journal of the European Mathematical Society},
     pages = {1859--1883},
     publisher = {mathdoc},
     volume = {14},
     number = {6},
     year = {2012},
     doi = {10.4171/jems/349},
     url = {http://geodesic.mathdoc.fr/articles/10.4171/jems/349/}
}