1. Vinberg G.G., “Biological processions and self-purification in polluted river areas”, (Moscow 1972)
2. Mustafoyeva B.O., Shamsiyev N.А, “Biological wastewater treatment”. Important environmental factors of sustainable development. (Bukhara 2013)
3. Mustafoyeva М, SHaripova М, Ecological analysis of biological ponds of wastewater treatment plants 2. Bukhara “Important environmental factors of sustainable development (Bukhara 2013)
4. Pardayev Sh, Niyozova F., KHayriyeva D., “Important environmental factors of wastewater treatment”. “Factors to mitigate environmental problems in the region” (Bukhara. 2019)