L. L. Sedelnikova and O. L. Tsandekova, “THE SPECIFIC CONTENT AND ASH CONTENT OF SOME BIOGENIC ELEMENTS (N, S, P) IN LEAVES OF HER-BACEOUS PLANTS IN THE CITY OF ISKITIM OF THE NOVOSIBIRSK REGION”, JCPRM, no. 1, pp. 213-218, Mar. 2021.