to have written volumes 13–20 (eight chronological tables) and 26 (treatise on astronomy), the latter with the help of Ma Xu. As with the Records of the Grand Historian, Zhang Qian, a notable Chinese general who travelled to the west, was a key source for the cultural and socio-economic data on the Western Regions contained in the 96th fascicle. The "Annals" section and the three chapters covering the reign of Wang Mang were translated into English by Homer H. Dubs. Other chapters have been rendered into English by A. F. P. Hulsewé, Clyde B. Sargent, Nancy Lee Swann, and Burton Watson. The text includes a description of the Triple Concordance Calendar System 三統曆 developed by Liu Xin in fascicle 21. This is translated to English by Cullen. Ban Gu's history set the standard for the writings of later Chinese dynasties, and today it is a reference used to study the Han period. It is regarded as one of the "Four Histories" 四史 of the Twenty-Four Histories canon, together with the Records of the Grand Historian, Records of the Three Kingdoms and History of the Later Han. Annals Ji (紀, annal), 12 volumes. Emperors' biographies in strict annal form, which offer a chronological overview of the most important occurrences, as seen from the imperial court. Chronological tables Biao (表, tables), 8 volumes. Chronological tables of important people. Treatises Zhi (志, memoirs), 10 volumes. Each treatise describes an area of effort of the state. Biographies Zhuan (傳, exemplary traditions, usually translated as biographies), 70 volumes. Biographies of important people. The biographies confine themselves to the description of events that clearly show the exemplary character of the person. Two or more people are treated in one main article, as they belong to the same class of people. The last articles describe the relations between China and the various peoples at and beyond the frontiers, including the contested areas of Ba in present-day Yunnan; Nanyue in present-day Guangdong, Guangxi, and Vietnam; and Minyue in present-day Fujian. Mention of Japan The people of Japan make their first unambiguous appearance in written history in this book (Book of Han, Volume 28, Treatise on Geography), in which it is recorded, "The people of Wo are located across the ocean from Lelang Commandery, are divided into more than one hundred tribes, and come to offer tribute from time to time." It is later recorded that in 57, the