Babaei, Reza, et al. “Detection of Overtone and Combined Peaks Using Mn Cu Helical Star-Shaped (pine-Tree-Like) Sculptured Thin Films in Surface-Enhanced Raman Spectroscopy”. Journal of Theoretical and Applied Physics, vol. 13, no. 4, Nov. 2023, https://doi.org/10.1007/s40094-019-00348-2.