1. L. N. Aleksandrova, “Humus as the system of polymeric compounds,” in Transactions of the Conference Dedicated to Anniversary of V. V. Dokuchaev (Izd. Akad. Nauk SSSR, Moscow, 1949), pp. 225–232.
2. L. N. Aleksandrova, “Modern concepts about nature of soil humus and their organomineral derivatives,” in Problems of Soil Science (Moscow, 1963) [in Russian].
3. V. V. Isaev, Synergy for Biologists: Introduction (Nauka, Moscow, 2005) [in Russian].
4. E. Yu. Milanovskii, Humic Soil Substances as the Natural Hydrophobic-Hydrophilic Compounds (GEOS, Moscow, 2009) [in Russian].
5. D. S. Orlov, Humic Acids of Soil and a General Theory of Humification (Moscow State University, 1990) [in Russian].