Picture taken on April 20, 2018 shows words written in Greek "Pharmacy of the Soul" on a plate at the door of the Abbey Library in north-eastern Switzerland's St. Gallen city. The library is one of the richest and oldest in the world and contains 170,000 works and some 2,100 original medieval handwritten manuscripts, including the earliest-known architectural plan drawn on parchment. (Xinhua/Xu Jinquan)