Optica will be performing scheduled maintenance on Wednesday (19 November) beginning at 18:00 ET. We apologize for any inconvenience this may cause. Thank you for your patience as we improve our services.
If you need assistance, Customer Service can be reached at +1 202.416.1907 (Worldwide) +1 800.766.4672 (US/Canada) or by emailing us at custserv@optica.org. Customer Service is available from 08:30 to 18:00 ET, Monday through Friday.
Extra OPEN
Jacob A. Riis. Hero Tales of the Far North (Macmillan, 1921).
P. Laporta and F. Zaraga. “Computer Design of Liquid Filters made of Aqueous Solutions of Transition Metal Ions,” Appl. Opt. 20, 2946 (1981).
“Niels Ryberg Finsen – Biographical,” The Nobel Prize, nobelprize.org.
