http://musicbrainz.org/search?query=wid%3A%225c0566d7-b8cd-336d-bb00-901492da54b7%22&type=work&limit=25&advanced=1 gives a single work with no artists. However, the work does have some recordings linked. The artists of a work is the set of all artist relationships AND all artists in artist credits of the top 3 linked recordings. "Top" recordings are defined as the recordings with the most amount of relationships. In this case, this should be:

ABBA
The Real Group
Harambee (Australian Choir)
Glee Cast
李玟
The Wedding Band

See Data::Artist->load_for_works to see how the direct search calculates this.