Serikbayeva Saltanat Zh, et al. “Peroxidation Of Saliva Lipids In Patients With Postcovid Syndrome During Hirudotherapy”. Journal of Population Therapeutics and Clinical Pharmacology, vol. 30, no. 11, May 2023, pp. 400-4, https://doi.org/10.47750/jptcp.2023.30.11.041.