Horswill P, O'Sullivan O, Phoenix GK, Lee JA, Leake JR. Base cation depletion, eutrophication and acidification of species-rich grasslands in response to long-term simulated nitrogen deposition. Environmental Pollution. 2008  ;155:336-349.

Lee JA, Caporn SJM, Carroll J, Foot JP, Johnson D, Potter L, Taylor AFS, Bates (E)JW, Ashton (E)NW, Ducken JG. Bryology for the Twenty-first Century. In: ; 1998. pp. 331-341.