Qīng xiá zǐ 青霞子 (“Master of Azure Mist”) — traditionally identified with Sū Yuánlǎng 蘇元朗, a semi-legendary SuíTáng alchemical author. Credited with KR5d0106 Lóng hǔ yuán zhǐ 龍虎元旨 and further alchemical writings. The actual dating of the received text(s) is probably 9th–10th century.