ANNA RINGSTROM and SIMON JOHNSON AMERICAN  poet Louise Glück won the 2020 Nobel Prize in Literature for works exploring family and childhood in an "unmistakable...voice that with austere beauty makes individual existence universal", the Swedish Academy said on Thursday. Academy Permanent Secretary Mats Malm said that Glück, 77, also a multiple winner of U.S. literary awards, was "surprised and happy" at the news when it came in the early morning hours U.S. time. She gave no immediate comment to journalists gathered outside her home in Cambridge, Massachusetts. A professor of English at Yale University, Glück first rose to critical acclaim…