Amanda Robinson and Robyn Hickie disappeared in 1979, and Gordana Kotevski disappeared in 1994.
Police have long suspected they were murdered.
In this episode of Local Lens*, NBN News Presenter Jane Goldsmith takes us through her close coverage of the story.
*Local Lens is a podcast series produced by University of Newcastle journalism students in collaboration with NBN News journalists. It explores major stories from the Hunter in depth, with the NBN reporters who investigate them. This podcast was produced by Ben Clifford, Grace Clegg and Rachel Lee.