E. A. Reshetnyak, “Separate sorption-spectroscopic determination of Pb(II), Mn(II), Co(II), Ni(II), Cd(II), Cu(II), Zn(II) in their mixture using the reagent indicator paper”, Khark. Univ. Bull. Chem. Ser., no. 22, pp. 210-219, Dec. 2013.