@ARTICLE{Auroux-00,
   author = {Veers\'e, F. and Auroux, D. and Fisher, M.},
   title = {Limited-memory {BFGS} diagonal preconditioners for a data assimilation problem in meteorology},
   journal = {Optim. Engineer.},
   volume = {1.3},
   pages = {323--339},
   year = {2000},
}