@TechReport{ETHAN_the_Evolutionary_Trees_and_Natural_History_Ontology,
  author = "Cynthia  Parr and Joel  Sachs and Andriy  Parafiynyk and Taowei  Wang and Roger  Espinosa and Tim  Finin",
  title = "{ETHAN: the Evolutionary Trees and Natural History Ontology}",
  month = "November",
  year = "2006",
  organization = "Computer Science and Electrical Engineering",
  series = "technical report",
  institution = "University of Maryland, Baltimore County",
}