Zavhorodnii , A., V. Bilushko, A. Paliy, M. Kalashnyk, N. Kalashnyk, and A. Paliy. “Freeze-Drying Improved the Stability of Tuberculin Purified Protein Derivative (PPD) in Mammals”. Problems of Cryobiology and Cryomedicine, vol. 32, no. 1, June 2022, pp. 63–67, doi:10.15407/cryo32.01.063.