P. M. Zubov, L. A. Babijchuk, V. V. Ryazantsev, and O. L. Timchenko, “Effect of cryoprotectant PEO-1500 and processing regimens on erythrocyte membrane asymmetry during cryopreservation”, Probl Cryobiol Cryomed, vol. 15, no. 3, pp. 573–574, Sep. 2005.