Manual on methods and criteria for harmonized sampling, assessment, monitoring and analysis of the effects of air pollution on forests : Part XIII Manual on methods and criteria for harmonized sampling, assessment, monitoring and analysis of the effects of air pollution on forests : Part XIII, ICP Forests, 2010, 978-3-926301-03-1 Manual on methods and criteria for harmonized sampling, assessment, monitoring and analysis of the effects of air pollution on forests.2010, 1-16