5 books that are not as famous in the USA as they should be

I don't usually book blog, but I have been reading a really great Russian sci-fi novel this week, and I realized that probably not many people on the other side of the Pond have ever had a chance to read it. I have made a list earlier of 6 books that need an English translation a.s.a.p.; this time, I would like to make a list of books that are already available in English, but not well known and kinda hard to find.
Please take this as a cry for help: I want my American friends to experience these awesome stories and be able to talk to me about them!

Boris and Arkady Strugatsky: Monday begins on Saturday
Imagine if a Russian Terry Pratchett wrote Harry Potter. That's exactly what this book reads like, with a dash of Doctor Who in the mix, all in glorious Soviet sci-fi fashion. It is essentially the parody of bureaucracy and academia, in which magic, witchcraft and folklore are all supervised from a scientific institute filled with weird researchers and professors that have never done anything useful. Hilarious, especially if you have ever been in academia. Or bureaucracy.

Vladimir Obruchev: Plutonia
Still on the topic of Russian science-fiction. This story, essentially, is their version of Journey to the Center of the Earth. Except, in this case our heroes are Russian scientists that do everything the accurate way: They document, they experiment, they collect and conserve samples, and they take their sweet time exploring the world of dinosaurs and cavemen. No mas, no fuss, exciting scientific solutions to being chased by giant ants. Neil deGrasse Tyson's wet dream.

Michael Ende: Momo
The true masterpiece from the author of The Neverending Story (which, by the way, is also sadly underrepresented in American bookstores. Most people think it was only a movie, which makes me want to hit something with the book.) Momo is the tale of a strange orphan girl who tries to stop a worldwide conspiracy of well-dressed businessmen stealing free time from people. A story with lovable characters (one of them is a storyteller!), and a deep message about what we decide to spend our time on.

Selma Lagerlöf: The wonderful adventures of Nils
Also the basis of one of the best cartoons of my childhood, this book tells the story of a young boy who gets transformed into a tiny version of himself by a gnome to learn a lesson. He embarks on a journey with a flock of wild geese and a domestic goose from his own backyard, to learn about the life of animals, and the many wonders of Sweden.

Tove Jansson: The Moomins
Talking about the cartoons of my childhood: While the artwork is adorable, The Moomins books are also a great read for children. And adults. And everyone. A family of trolls and their various friends of all shapes and sizes get into fascinating - and often supernatural - adventures.

Bonus: I wrote on MopDog about two amazing (I'm picky) Hungarian historical novels that are also available English, but sadly unknown. You can check out the post here.