Tikhonov Vladimir Evgenievich, Rashidova Sayyora Sharafovna, P. K. K. “Oligochitosan and Oligochitosan Ascorbat: Preparation and Properties”. International Journal of Modern Agriculture, vol. 10, no. 2, Mar. 2021, pp. 1244 -62, http://modern-journals.com/index.php/ijma/article/view/851.