《资治通鉴·梁纪·梁纪一》
每通施用三弦，黄钟弦用二百七十丝，长九尺；应钟弦用一面四十二丝，长四尺七寸四分多，中间的十律，以此而递减。
每通施三弦，黄钟弦用二百七十丝，长九尺，应钟弦用一百四十二丝，长四尺七寸四分差强，中间十律，以是为差。
Each Tong uses three strings, the Huang Zhong string uses 270 silks, nine feet long; the Ying Zhong string uses 142 silks on one side, more than four feet and seven inches and four minutes long, and the ten laws in the middle decrease accordingly.