optiska dokument
type: Concept
preferred label: optical recordings @en
preferred label: optiset tallenteet @fi
narrower: WORM-skivor

digitala dokument
type: Concept
preferred label: digital recordings @en
preferred label: digitaaliset tallenteet @fi
narrower: WORM-skivor

WORM-skivor
type: Concept
broader: optiska dokument
broader: digitala dokument
in scheme: conceptscheme
preferred label: worm discs @en
preferred label: WORM-levyt @fi