Electron-paramagnetic resonance and infrared spectroscopic research of the structure of a southfield Polyvinylidene difluoride near the percolation thresholdAbdusalam Umarov, Dilnavoz Kamolova and Makhmudjon KurbonovE3S Web Conf., 264 (2021) 05009DOI: https://doi.org/10.1051/e3sconf/202126405009