Kopittke, P.M., Kinraide, T.B., Wang, P., Blarney, F.P.C., Reichman, S.M. and Menzies, N.W. (2011) Alleviation of Cu and Pb rhizotoxicities in cowpea (Vigna unguiculata) as related to ion activities at root-cell plasma membrane surface. Environmental Science & Technology, 45, 4966-4973.