• A unified classification on alien species based on the magnitude of their environmental impacts 

      Blackburn, T.M.; Essl, F.; Evans, T.; Hulme, P.E.; Jeschke, J.M.; Kuhn, I.; Kumschick, S.; Markova, Z.; Mrugala, A.; Nentwig, W.; Pergl, J.; Pysek, P.; Rabitsch, W.; Ricciardi, A.; Richardson, D.M.; Sendek, A.; Vila, M.; Wilson, J.R.U.; Winter, M.; Genovesi, P.; Bacher, S. (Public Library of Science, 2014-05-06)
      Species moved by human activities beyond the limits of their native geographic ranges into areas in which they do not naturally occur (termed aliens) can cause a broad range of significant changes to recipient ecosystems; ...