Power S, Ashmore MR, Cousins DA. Impacts and fate of experimentally enhanced nitrogen deposition on a British lowland heath. . Environmental Pollution. 1998  ;102:27-34.

Uren SC, Ainsworth N, Power S, Cousins DA, Huxendurp LM, Ashmore MR. Long term effects of ammonium sulphate on Calluna vulgaris. Journal of Applied Ecology . 1997  ;34:208-216.

Power S, Ashmore MR, Cousins DA, Ainsworth N. Long term effects of enhanced nitrogen deposition on a lowland dry heath in southern Britain. . Water, Air and Soil Pollution. 1995  ;85:1701-1706.