IATE-1370174

Subject Field	unknown
Is Reference of	Gruppengeschwindigkeit-de#Sense
	Velocità di gruppo-it#Sense
	Gruppehastighed-da#Sense
	Groepsnelheid-nl#Sense
	Grupphastighet-sv#Sense
	Ταχύτητα ομάδας-el#Sense
	Velocidade de grupo-pt#Sense
	Envelope velocity-en#Sense
	Vitesse de groupe-fr#Sense
	Ταχύτητα περιβάλλουσας-el#Sense
	Group velocity-en#Sense
	Ryhmänopeus-fi#Sense
	Velocidad de grupo-es#Sense