That shop in the famous Singer building is the Dom Knigi, House of books, by far the best bookstore in SPb. In the basement is a department Russian history, also with books on the Romanvovs, but all books in Russian. A chain with shops all over Spb, several of them on Nevsky Prospekt is called Bukvoed. However, their history departments are rather poor. A shop close to the Dom Knigi, just off Nevsky Prospekt in a basement on Malaya Konyushennaya 9, orthodox/christian bookstore Slovo has a small collection of books on Russian history, for ex. Buexhoeveden's two volume memoirs (in Russian) and last week they had three of the four volumes appeared so far of the biographical materials of GD Sergei Alexandrovich (also in Russian). The two volume albums of the 1903 Costume Ball you will not find in these shops. A few copies are offered on internet. Most second hand bookshops have disappeared and the main book business (new, old and rare books) is being done through the internet, in Russia too!