1, Historical Events: Both books recorded some historical events between China and India (Wu Tianzhu) in the Tang Dynasty, such as wars and diplomatic contacts.
2. Background: Both books introduced the historical background and diplomatic relations between China and India (Wu Tianzhu) in the Tang Dynasty.
3. Cultural exchanges: Both books recorded the cultural exchanges between China and India (Wu Tianzhu) during the Tang Dynasty, including the exchanges in Buddhism, art, language and literature.