@InProceedings{l08-p94-105,
  AUTHOR    = {Oscar~H. Ibarra and Juhani Karhum\"aki and Alexander Okhotin},
  TITLE     = {On Stateless Multihead Automata: Hierarchies and the Emptiness Problem},
  YEAR      = 2008,
  BOOKTITLE = {Proc.~of the 8th Latin American Symposium on Theoretical Informatics (LATIN'08)},
  ADDRESS   = {B\'uzios, Brazil},
  PAGES     = {94--105},
  KEYWORDS  = {}}