Paul Fitzgerald and Elizabeth Gould have traveled to and from Afghanistan for the past 30 years. They were the first American journalists to acquire permission to enter Afghanistan behind Soviet lines in 1981 for CBS News and produced a documentary, "Afghanistan Between Three Worlds," for PBS. For twenty years they have continued to follow events in Afghanistan and write about its history and US involvement. They are out with a new book, Invisible History: Afghanistan's Untold Story.