O. Krupko, L. Shcherbak, Y. Khalavka, V. Pylypko, K. Holovata, and S. Udod, “Influence of Cu2+ ions on the optical properties of CdS/L-Cys colloid solutions”, Phys.Chem.Sol.State, vol. 26, no. 4, pp. 713–717, Nov. 2025.