@inbook{9,
  author = {Hawksworth D.},
  title = {Bioindication: Calibrated scales and their utility},
  year = {2002},
  journal = {Monitoring with Lichens – Monitoring Lichens},
  publisher = {Kluwer Academic Publishers},
  address = {Dordrecht, The Netherlands},
  issn = {978-1-4020-0430-8},
  doi = {10.1007/978-94-010-0423-7_3},
  language = {eng},
}