“…In more recent times, it made its appearance in the context of the AdS/CFT correspondence [17,18], brane solutions [19,20,21], plane waves [22,23] and homogeneous backgrounds [24], with the general construction appearing for the first time in [25] for d=11 and [26] for d=10 supergravities. Since then, a number of other supergravity theories have been treated, such as d=6 [27], d=10 conformal in [28] and d=4 (off-shell, minimal) in [29].…”