Extensions of p-adic vector measures

For R being a separating algebra of subsets of a set X, E a complete Hausdorff non-Archimedean locally convex space and m: R -> E a bounded finitely additive measure, it is shown that: (a) If m is sigma-additive and strongly additive, then m has a unique sigma-additive extension m(sigma) on the sigma-algebra R-sigma generated by R. (b) If m is strongly additive and tau-additive, then m has a unique tau-additive extension m(tau) on the sigma-algebra R-bo of all tau(R)-Borel sets, where tau(R) is the topology having R as a basis. Also, some other results concerning such measures are given.