Tipping E, Henrys PA, Maskell LC, Smart SM. Nitrogen deposition effects on plant species diversity; threshold loads. Environmental Pollution. 2013  ;179:218-223.

Stevens CJ, Smart SM, Henrys PA, Maskell LC, Crowe A, Simkin J, Cheffings CM, Whitfield C, Gowing DJG, Rowe EC, et al. Terricolous lichens as indicators of nitrogen deposition: Evidence from national records. Ecological Indicators. 2012  ;20:196-203.

Stevens CJ, Smart SM, Henrys P, Maskell LC, Walker KJ, Preston CD, Crowe A, Rowe E, Gowing DJ, Emmett BA. Collation of evidence of nitrogen impacts on vegetation in relation to UK biodiversity objectives. JNCC; 2011.

Emmett BA, Rowe EC, Stevens CJ, Gowing DJ, Henrys PA, Maskell LC, Smart SM. Interpretation of evidence of nitrogen impacts on vegetation in relation to UK biodiversity objectives. JNCC; 2011.

Maskell LC, Smart SM, Bullock JM, Thompson K, Stevens CJ. Nitrogen deposition causes widespread species loss in British Habitats. Global Change Biology. 2010  ;16: 671-679.

Stevens CJ, Maskell LC, Smart SM, Caporn SJM, Dise NB, Gowing DJ. Identifying indicators of atmospheric nitrogen deposition impacts in acid grasslands. Biological Conservation. 2009  ;142:2069-2075.