DVDplus is a format similar to DualDisc, see https://en.wikipedia.org/wiki/DVDplus I'm not entirely sure how the two differ, but they have different logos and both Wikipedia and Discogs have them separate.

I've tagged some releases already - https://musicbrainz.org/tag/format-dvdplus/release
There are more releases on http://www.discogs.com/search/?q=&format_exact=DVDplus