La compilation Billions and Billions : Thoughts on Life and Death at the Brink of the Millennium, published in 1997 after Sagan 's death, contains essays written by Sagan, such as his views on abortion, and his widow Ann Druyan' s account of his death as a skeptic, agnostic, and freethinker.
La compilation Billions and Billions : Thoughts on Life and Death at the End of the Millennium, publié après la mort de Sagan, contient des essais écrits par Sagan, comme ses opinions sur l'avortement, et le récit d'Ann Druyan sur sa mort en tant que non-croyant.