@InProceedings{HennigKiefel,
  author = 	 {Hennig, P. and Kiefel, M.},
  title = 	 {Quasi-{N}ewton methods -- a new direction},
  booktitle =    {Int. Conf. on Machine Learning (ICML)},
  year = 	 {2012},
  volume = 	 {29}
}