what is the base currency of the ukrainian people's republic of soviets which can be used in caucasus viceroyalty ?
SELECT DISTINCT var_uri where brack_open dbr_Ukrainian_People's_Republic_of_Soviets dbp_currency var_uri sep_dot dbr_Caucasus_Viceroyalty_ attr_open 1785–96 attr_close dbp_currency var_uri brack_close