reverse, these inscriptions include: Kāng Xī Tōng Bǎo cash coins produced at the Ministry of Revenue and the Ministry of Public Works in the capital city of Beijing are excluded from these poems. Because of the popularity of the Kangxi poem coins many later versions of the poem coins were made where the Kangxi era mint marks are used but other inscriptions such as the Yongzheng Tongbao, Daoguang Tongbao, Guangxu Tongbao, Etc. are used on the obverse. Coin-swords made from Qing dynasty cash coins with the inscription Kangxi Tongbao are considered to be the most effective, this is because the reign of the Kangxi Emperor of the Qing dynasty lasted an entire 60-year cycle of the Chinese calendar and thus according to feng shui cash coins with this inscription represent "longevity". See also List of Chinese cash coins by inscription References Citations Sources T'ang Yu K'un.《制錢通考》(A comprehensive study of chinese coins) . Wei Chien Yu.《中國近代貨幣史》(Currency history of Modern China) . 群聯出版社，1955. Ting Fu Pao.《古錢大辭典》(A dictionary of ancient Chinese coins). 中華書局. Werner Burger. Ch'ing Cash until 1735, Mei Ya Publications, Inc., 1976. Pang Hsin Wei. 《中國貨幣史》(The Currency History of China). 上海人民出版社, 1988. /K·47. 張作耀. 《中國歷史便覽》(China History Bianlan)，人民出版社，1992, /K·53. Hartill, David, Qing cash, Royal Numismatic Society Special Publication 37, London, 2003. External links Coins of ancient China Kangxi Emperor Chinese numismatics Cash coins by inscription