TY - BOOK ID - 127097148 TI - Topographic instructions of the United States geological survey : ER-55 plotter procedures : instructions in the standard operating procedures for the ER-55 plotter, including a description of equipment PY - 1961 PB - Washington, D.C.: Government printing office, DB - UniCat UR - https://www.unicat.be/uniCat?func=search&query=sysid:127097148 AB - ER -