Domestic Security Protection Bureau, the department of the Ministry of Public Security responsible for political security, monitoring dissidents, religious groups and activities deemed a threat to state stability
"Duke Li of Wei Answering Emperor Taizong of Tang", military treatise attributed to Li Jing 李靖[lǐ jìng] and one of the Seven Military Classics of ancient China 武经七书[wǔ jīng qī shū]