docs: Add reference to references.
docs: Add reference to references.

nie-ine/Knora,dhlab-basel/Knora,nie-ine/Knora,musicEnfanthen/Knora,dhlab-basel/Knora,nie-ine/Knora,nie-ine/Knora,dhlab-basel/Knora,musicEnfanthen/Knora,dhlab-basel/Knora,musicEnfanthen/Knora,nie-ine/Knora,dhlab-basel/Knora,dhlab-basel/Knora,musicEnfanthen/Knora,dhlab-basel/Knora,nie-ine/Knora,musicEnfanthen/Knora,musicEnfanthen/Knora,musicEnfanthen/Knora