Fizika Tverdogo Tela, 1990 Volume 32, Issue 8,Pages 2306–2310(Mi ftt6297)
Determination of electric field gradient tensor parameters at copper sites in $\mathrm{Bi}_{2}\mathrm{Sr}_{2}\mathrm{CaCu}_{2}\mathrm{O}_{7}$ and $\mathrm{YBa}_{2}\mathrm{Cu}_{3}\mathrm{O}_{7}$ by Mossbauer spectroscopy