1. O. I. Vinogradova, Doctoral Dissertation in Mathematics and Physics (Moscow, 2000).
2. G. I. Glebova, “Determination of the size and shape of humic acid particles using electron microscopy,” Pochvovedenie, No. 7, 115–117 (1972).
3. I. P. Evdokimov and A. P. Losev, Natural Nanoobjects in Oil and Gas Environments (Ross. Gos. Univ. Nefti Gaza im. I. M. Gubkina, Moscow, 2008) [in Russian].
4. N. I. Laktionov, Yu. A. Rybakova, L. A. Sysoev, and V. I. Chaplygin, “Peculiarities of the structure of hydrosols of humic acids and sodium humates,” Pochvovedenie, No. 7, 129–133 (1992).
5. E. Yu. Milanovskii, Soil Humic Substances as Natural Hydrophobic–Hydrophilic Compounds (GEOS, Moscow, 2009) [in Russian].