Björn L. O., Callaghan T. V., Gehrke C., Gwynn-Jones D., Lee J. A., Johanson U., Sonesson M. and Buck N. D. (1999) “Effects of ozone depletion and increased ultraviolet-B radiation on northern vegetation”, Polar Research, 18(2), pp. 331-337. doi: 10.3402/polar.v18i2.6592.