in which military conflict were gian galeazzo visconti and gian galeazzo visconti commanders ?
SELECT DISTINCT var_uri where brack_open var_uri dbo_commander dbr_Gian_Galeazzo_Visconti sep_dot var_uri dbo_commander dbr_Gian_Galeazzo_Visconti sep_dot var_uri a dbo_MilitaryConflict brack_close