Study of foreign tributary system in the Tang dynasty 并列题名:Study of foreign tributary system in the Tang dynasty Study on the four-ritual system in the Song Dynasty Study of the imperial examination system in the Tang dynasty change of foreign-related system in the late Qing dynasty Study on the tax legal system in the Qing Dynasty Study of festivals in the Tang dynasty Study of foreign cultures in Han dynasty a study of military rites in tang dynasty 并列题名:Study of the imperial examination system in the Tang dynasty