อ้างอิง ของ แว่นขยาย

  1. ↑ The history of the telescope by Henry C. King, Harold Spencer Jones Publisher Courier Dover Publications, 2003 Pg 25 ISBN 0-486-43265-3, ISBN 978-0-486-43265-6
  2. ↑ Kriss, Timothy C.; Kriss, Vesna Martich (April 1998). "History of the Operating Microscope: From Magnifying Glass to Micro neurosurgery". Neurosurgery. 42 (4): 899–907. doi:10.1097/00006123-199804000-00116. PMID 9574655.