TY - JOUR AB - AU - Arthur C Trowbridge DA - 1959/7// DO - 10.17077/0031-0360.23352 IS - 7 VL - 40 PB - State Historical Society of Iowa PY - 1959 TI - Facts and Principles of Glaciation T2 - The Palimpsest UR - https://pubs.lib.uiowa.edu/palimpsest/article/id/23352/ ER -