@article{lemarechal-sagastizabal-1997,
  author	= {{Lemar{\'e}chal}, C. and Sagastiz{\'a}bal, C.},
  title		= {Variable metric bundle methods_ from conceptual to implementable forms},
  journal	= {Mathematical Programming},
  volume	= {76},
  number	= {3},
  pages		= {393--410},
  year		= {1997},
}