where is the headquarters of the company which runs the west midlands bus routes 81 in minnesota ?
SELECT DISTINCT var_uri where brack_open dbr_West_Midlands_bus_routes_81,_81E_and_81W_ attr_open Coventry attr_close dbp_operator var_x sep_dot var_x dbp_headquarters var_uri sep_dot var_x a dbo_Organisation brack_close