Yīn dān nèi piān 陰丹內篇
Inner Chapter of the Yīn Elixir
Anonymous; SòngYuán
A short Daoist inner-alchemical treatise on the yīn dān 陰丹 — the female / passive aspect of the elixir work. Preserved as DZ 1189 / CT 1189 (Tài qīng bù 太清部).
Dating. SòngYuán. Dynasty: 宋-元.