Korshykov, I., N. Shevchuk, and E. Guseynova. “The Changes of Colouring and Content of Photosynthetic Pigments in Unevenaged Needles of Picea Pungens Engelm. In Conditions of Urban Plantings”. Plant Introduction, Vol. 81, Mar. 2019, pp. 82-89, doi:10.5281/zenodo.2650471.