 These Ban Liang cash coins were quite notable because they have never been documented in any prior Chinese numismatic literature.According to the author of the article, these "drilled hole" Ban Liang cash coins were produced by the State of Qin somewhere around the middle to the end of the Warring States period.These "drilled holes" are mostly found outside of the areas where the Chinese characters are located and the authors of the 2010 article assumes that they have been drilled into them after they have already been cast, meaning that these holes were not the result of a poor manufacturing process.