@article{GDZPPN002335131,
title = {Hyper K\"ahler and quaternionic K\"ahler geometry.},
journal = {Mathematische Annalen},
volume = {291},
year = {1991},
pages = {421-450},
zbl = {0711.53051},
url = {http://dml.mathdoc.fr/item/GDZPPN002335131}
}
Swann, Andrew. Hyper Kähler and quaternionic Kähler geometry.. Mathematische Annalen, Tome 291 (1991) pp. 421-450. http://gdmltest.u-ga.fr/item/GDZPPN002335131/