13a. At some point during the boom, there is the bust (5) B-s--
16a. Magnificent (7) ----o-e
20a. Sample a commercial, one hears, for a criminal group (5) T-I--
RTE No.26.
19d. One to give others much to think about (8) E-u-s---
28a. Took the Scots in, so it did,...which brought the great into Britain (3,2,5))
17d. Must be established to have begun on top (7,2) -t-r-o---