@InProceedings{l92-p448-459,
  AUTHOR    = {Jos\'e~D.~P. Rolim},
  TITLE     = {On the Density and Core of the Complexity Classes},
  YEAR      = 1992,
  BOOKTITLE = {Proc.~of the 1st Latin American Symposium on Theoretical Informatics (LATIN'92)},
  ADDRESS   = {S\~ao Paulo, Brazil},
  PAGES     = {448--459},
  KEYWORDS  = {}}