Ershov, Y.L. Algebra and Logic (2002) 41: 374. doi:10.1023/A:1021703629535
The main model-theoretic results on multi-valued fields with near Boolean families of valuation rings obtained in [1, Ch. 4, Sec. 4.6] are generalized along two lines: we weaken the restriction on being absolutely unramified to a condition of being finite for an absolute ramification index, and we combine, through context, Theorems 4.6.2 and 4.6.4 (4.6.3 and 4.6.5).
multi-valued field Boolean family of valuation rings absolute ramification index