Instance of: http://www.w3.org/2004/02/skos/core#Concept
Subject Field Subject Field/6826
Is Reference of Optical signal-en#Sense
Optisches Signal-de#Sense
Signal visible-fr#Sense
Optinis signalas-lt#Sense
Optisch signaal-nl#Sense
Οπτικό σήμα-el#Sense
Optikai jel-hu#Sense