@article{LindenbergerKlieglBaltes1992,
  author    = {Lindenberger, Ulman and Kliegl, Reinhold and Baltes, Paul B.},
  title     = {Professional expertise does not eliminate negative age differences in imagery-based memory performance during adulthood},
  year      = {1992},
  language  = {en}
}
@article{BaltesKliegl1992,
  author    = {Baltes, Paul B. and Kliegl, Reinhold},
  title     = {Further testing of limits of cognitive plasticity : negative age differences in a mnemonic skill are robust},
  issn      = {0012-1649},
  year      = {1992},
  language  = {en}
}