主题：【求助】(ok)—求助几篇外文文献，谢谢！

[1] T. H. Nash III, E. H. Nash; Sensitivity of mosses to sulfur dioxide; Oecologia; 1974, 17: 257-263
  http://www.springerlink.com/content/xt14325150030286/

[2] P. Karolewski, M. J. Giertych, J. Oleksyn1, et al.; Differential reaction of Pinus sylvestris, quercus robur and Q. petraea trees to nitrogen and sulfur pollution; Water, Air, & Soil Pollution; 2005, 160: 95-108
  http://www.springerlink.com/content/r762l56304r36j36/

[3] J.M.Dasch, Dry deposition of sulfur dioxide or nitric acid to oak, elm and pine leaves; Environmental Pollution (United Kingdom); 1989, 59: 1-16
http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6VB5-4914S67-DV-1&_cdi=5917&_user=44062&_orig=search&_coverDate=12%2F31%2F1989&_sk=999409998&view=c&wchp=dGLbVlz-zSkzS&md5=8d0634271b54513239c314aa87cb34f4&ie=/sdarticle.pdf

[4] W. Dmuchowski, A. Bytnerowicz; Monitoring environmental pollution in Poland by chemical analysis of Scots pine (Pinus sylvestris L.) needles; Environmental Pollution; 1995, 87: 87-104

  http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6VB5-3XG1XGR-D&_user=1915929&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_version=1&_urlVersion=0&_userid=1915929&md5=1fb2ac06b2c363584538f506c9af5787