The division of "early, prosperous, middle and late" in Tang poetry started from which of the following works?

The split began with Liu Yiqing's Taoan Dream. In Dream of Tao 'an, Liu Yiqing divided the creation years of Tang poets and divided the development of Tang poetry into four periods: early Tang, prosperous Tang, middle Tang and late Tang. This division has been widely recognized by later generations and has become one of the important methods to study Tang literature.