Analysis of information sources in references of the Wikipedia article "Silla–Tang War" in English language version.
安東都護府總章元年九月,司空李勣平高麗。高麗本五部,一百七十六城,戶六十九萬七千。其年十二月,分高麗地為九都督府,四十二州,一百縣,置安東都護府於平壤城以統之。In the ninth month of the first year of the Zongzhang era [668], the Minister of Works Li Ji pacified Goguryeo. Originally Goguryeo had 5 regions, 176 cities, and 697,000 households. In the twelfth month of that year, Goguryeo's territory was divided into 9 commanderies, 42 prefectures, and 100 counties. The Andong Protectorate was situated at Pyeongyang to govern it.
上元三年二月,移安東府於遼東郡故城置。儀鳳二年,又移置於新城。In the second month of the third year of the Shangyuan era [676], the seat of Andong was moved to the Old City of Liaodong. In the second year of the Yifeng era [677], it was move again, this time to Xincheng.