Near the Yaesu South entrance of Tokyo station, there is Yaesu Book Center. As it has a history that it was founded because the bookseller that keeps any book was wanted, it stocks a very good selection. It is a representative bookseller in Tokyo. Especially, it keeps best selection of scientific and technological books. However, it may be difficult to find books you want as it is in disorder a little. Of course, it has foreign books. This bookseller was closed sometimes on Sunday, as is expected from the place, but these days they are almost open throughout the year and business hours is long. (Update: 2002.11.09)
Going to Mitsukoshi-mae Station through the Eidan subway Hanzomon line from Jimbocho, and cross the well-known Nihonbashi Bridge, which is a bridge across a river anyway, you will find the Nihonbashi main store of Maruzen. It is also well-known as a dealer of foreign books and a publisher. Such as "Rika Nempyo (Chronological Scientific Tables)". The nearest stations are Nihonbashi Station of the subway, and the Yaesu Noruth entrance of Tokyo staton of JR. It is sometimes closed on Sunday, as is expected from the place. They opened the Maru-biru (Marunouchi Building) branch, though I don't have been there yet. (Update: 2002.11.09)