 Copies of his works translated by Robert M. Green are held at the National Library of Medicine in Bethesda, Maryland.In 2018, the University of Basel discovered that a mysterious Greek papyrus with mirror writing on both sides, which was at the collection of Basilius Amerbach, a professor of jurisprudence at the University of Basel in the 16th century, is an unknown medical document of Galen or an unknown commentary on his work.The medical text describes the phenomenon of ‘hysterical apnea’.