Question: Maureen Jane Teefy and Helen Slater both starred in what 1984 film directed by Jeannot Szwarc? 
Sentence (from "Supergirl (film)"): Supergirl is a 1984 British superhero film directed by Jeannot Szwarc and written by David Odell, based on the DC Comics character of the same name and serves as a spin-off to Alexander and Ilya Salkind's "Superman" film series.
Relevant evidence: Yes