A retrospective on NPS invasive species policy and management Author Drees L. Journal/Series Park Science | Vol. 22(2); 21 - 26; 6 p. Date 2004 Source IUCN (ID: ANA-073793) Publisher | Place of publication National Park Service / U.S. Department of the Interior | Washington, DC, USA Document type Article in periodical Language English Country/Territory United States of America Subject Wild species & ecosystems Keyword Alien species Management/conservation National parks