de Crespigny 2007, p. 555. Cao Rui's biography in the Sanguozhi recorded that the Duke of Shanyang died on the gengyin day of the 3rd month of the 2nd year of the Qinglong era of Cao Rui's reign. This date corresponds to 21 April 234 in the Gregorian calendar. Original quote in Sanguozhi vol. 3: [青龍二年]三月庚寅,山陽公薨 de Crespigny, Rafe (2007). A Biographical Dictionary of Later Han to the Three Kingdoms 23-220 AD. Handbook of Oriental Studies. Section 4: China, Volume 19. Leiden: Brill. doi:10.1163/ej.9789004156050.i-1311.7. ISBN9789004156050.