Online bookstores and book search engines

[Φιλόσοφος]

I buy a lot of books. Here are some bookstores I like, from the perspective of someone with a shipping address in the U.S.:

General purpose:

http://www.AbeBooks.com My absolute favorite. This is the one I use the most. Here you can find books in many different languages, used and new, from English to German, Danish, Polish or Sanskrit. Search here often. Use the ISBN when possible.

English

http://www.Amazon.com Almost never order directly from them though. The different sellers on the marketplace is what makes Amazon valuable.
http://www.BookDepository.com Sometimes they have titles at a competitive price.

French

http://www.Amazon.de Yes, that is not a typo. You will find that most of the time, French books are more economical at the German Amazon site. Search using ISBN.
http://www.PriceMinister.com The best source that I know of for out-of-print French books.
http://www.Amazon.com Many third-party sellers of French books list their books here.

German

http://www.BookDepository.com Many times, German books are the most economical here.
http://www.Amazon.com Third party sellers.
https://www.BookLooker.de/ My favorite source for out-of-print German books.

Spanish

Local bookstores I use:
http://www.LibreriaLerner.com.co/
https://www.LibreriaNacional.com/
http://www.Panamericana.com.co/

Norwegian

http://www.Bokkilden.no/ Expensive and annoying, but what else is there?

Scandinavian antiquarian sellers

http://www.Antikvariat.net/

West European search engine

https://www.EuroBuch.com/

Polish

http://www.Empik.com/ Very good service. They ship via registered mail with tracking number.

Hungarian

https://www.Libri.hu/ Cannot exaggerate how good they are. They ship via UPS and orders are received after a few days. Prices are reasonable and service great. Highly recommended.

Romanian

http://www.Librarie.net/ They have shipped all of my orders via registered mail with tracking number. Service is good. Recommended.

Russian

http://www.Ozon.ru/ Excellent. They sell both new and out-of-print books. The used books I've ordered from them have arrived in perfect condition. They have sent all of my orders via UPS or DHL, delivering them a few days after shipment. Highly recommended.
http://www.Biblio-Globus.us/ In case something is out of stock at Ozon.
http://www.Kniga.com/ Very limited inventory, but they have good sales, and are located directly in the U.S.

Georgian

http://www.ProsperosBookshop.com/ Friendly service. They obtain books from you.
http://www.Parnasi.ge/ Useful as well.

Arabic

http://www.alKitab.com/ U.S. store.
http://www.alMaktabah.com/ Haven't ordered from them in several years.

Hindi, Sanskrit and other Indian languages

http://www.ExoticIndia.com/ Absolutely fabulous. They have frequent sales, and ship via DHL or UPS. Very, very good.
http://www.SamskritaBharatiusa.org/ Very special. This is an organization that is devoted to the teaching of Sanskrit. They offer many different books in Sanskrit such as modern novels and other types of light literature which provide a valuable opportunity to practice the language. They even publish a monthly magazine entirely in Sanskrit, something no student should pass up on.
http://www.mlbd.com/ A main publisher of Indian books.
http://www.DKAgencies.com/ Thorough inventory in all the principal Indian languages, but can be cumbersome to use.
http://www.IndiaClub.com/ A good source for Hindi books.
http://www.AbeBooks.com Particularly useful for Sanskrit books.

Japanese

https://www.Amazon.co.jp/ Obvious choice. Remarkable how economical shipping has become. Almost like ordering books locally.

[Ingaræð]

(Not sure if this is the right thread for this...)

I was wondering, do people normally use the websites listed to buy audiobooks too, or are there better websites for that?