 The main source of Khitan texts are monumental inscriptions, mostly comprising memorial tablets buried in the tombs of Khitan nobility.Only one monument in a Khitan script was known before the 20th century, the "Record of the Younger Brother of the Emperor of the Great Jin Dynasty" ("Langjun xingji" 郎君行記), which has stood in front of the tomb of Empress Wu of Tang since at least 1618.Until the 1920s it was believed to be written in the Jurchen script.