Reference
L. J. Sheppard, A. Crossley (2000): Responses of a Sitka Spruce Ecosystem after 4 Years of Simulated Wet N Deposition: Effects of NH4NO3 Supplied with and without Acidity (H2SO4 pH 2.5). – Phyton, Annales Rei Botanicae, Horn – 40_4: 169 - 174.