Hyperfine interactions at 181Hf(→181Ta) impurities implanted in Er2O3 and Gd2O3: structural and electronic dependence of the EFG in bixbyite sesquioxidesL. A. Errico, M. Rentería, A. F. Pasquevich, A. G. Bibiloni and K. FreitagEur. Phys. J. B, 22 2 (2001) 149-156DOI: https://doi.org/10.1007/PL00011141