Btwentynine

1 clue
Enola Gay, e.g. (and a hint to this puzzle's unusual feature)
Similar answers:
Agentninetynine
Btwentynine
Crashoftwentynine
Elevenfiftynine
Februarytwentynine
Fortynine
Fortynineacross
Fortyniner
Fortyninerbacks
Fortyniners
Itwentynine
Ninetynine
Sixtynineacross