Chikezie P.C, Akuwudike A. R and Chikezie C. M (2012) “Membrane stability and methaemoglobin content of human erythrocytes incubated in aqueous leaf extract of Nicotiana tabacum product”, Free Radicals and Antioxidants, 2(4), pp. 56–61. doi: 10.5530/ax.2012.4.10.