Issac Asimov's great novelization of the film
The well-known popular science writer Issac Asimov was so impressed by this film that he wrote the novelization of it. This was the only movie that Asimov ever did this for.
I came across my copy the other day, and would highly recommend anyone interested in the movie get a copy of it. Asimov greatly elaborates on concepts in the film. For example, he gives a fascinating discussion on miniaturization and how it might be accomplished. He also elaborates on the function of the human body and how things work in it.
If you liked the movie, definitely try and get your hands on Asimov's novelization. He adds a ton of info that wasn't able to be put into the movie.