They are also known as "Changduanju" (長短句/长短句, "lines of irregular lengths") and "Shiyu" (詩餘/诗馀, "that which is beside poetry").Typically the number of characters in each line and the arrangement of tones were determined by one of around 800 set patterns, each associated with a particular title, called "cípái" 詞牌/词牌. Originally they were written to be sung to a tune of that title, with set rhythm, rhyme, and tempo. The Song dynasty was also a period of great scientific literature, and saw the creation of works such as Su Song's "Xin Yixiang Fayao" and Shen Kuo's "Dream Pool Essays". There were also enormous works of historiography and large encyclopedias, such as Sima Guang's "Zizhi Tongjian" of 1084 or the "Four Great Books of Song" fully compiled and edited by the 11th century. Notable Confucianists, Taoists and scholars of all classes have made significant contributions to and from documenting history to authoring saintly concepts that seem hundreds of years ahead of time. Although the oldest surviving textual examples of surviving "ci" are from 8th century CE Dunhuang manuscripts, beginning in the poetry of the Liang dynasty, the "ci" followed the tradition of the "Shi Jing" and the "yuefu": they were lyrics which developed from anonymous popular songs into a sophisticated literary genre; although in the case of the "ci" form some of its fixed-rhythm patterns have an origin in Central Asia. The form was further developed in the Tang dynasty. Although the contributions of Li Bo (also known as Li Po, 701 – 762) are fraught with historical doubt, certainly the Tang poet Wen Tingyun (812–870) was a great master of the "ci", writing it in its distinct and mature form. One of the more notable practitioners and developers of this form was Li Yu of the Southern Tang Dynasty during the Five Dynasties and Ten Kingdoms period. However, the "ci" form of Classical Chinese poetry is especially associated with the poetry of the Song Dynasty, during which it was indeed a popular poetic form. A revival of the "ci" poetry form occurred during the end of the Ming dynasty and the beginning of the Qing dynasty which was characterized by an exploration of the emotions connected with romantic love together with its valorization, often in a context of a brief poetic story narrative within a "ci" poem or a linked group of "ci" poems in an application of the "chuanqi" form of short story tales to poetry.