It's difficult these days to get the Prokofiev sonatas. The scores I have for the later sonatas I had to buy in Germany. In Amerika, we are having troubles with the GATT Treaty, which extended the copyrights of Russian composers. This is from sheetmusicarchive.com:
" Also, ironically, most Russian sheet music editions published before
1973 are in the public domain. However, under terms of the 1996
GATT treaty, some Russian editions that were once in public domain
have had their copyrights restored! The more notable examples of this are
Shostakovich and Prokofiev editions published in the 1960s. There
is an American company called Dover Publications, Inc., which reprints
public domain sheet music editions. It used to publish reprints of
1950s/1960s Russian editions of Prokofiev's Sonatas and shorter piano
works, and Shostakovich's 24 Preludes and Fugues for piano. But since
the recent GATT treaty the editions went back into copyright, even though
they were once public domain, and now Dover has discontinued
republication of these editions."
When I bought my Dover edition of Shostakovich Preludes & Fugues, the only reason it was in the store was because when they heard it was to be discontinued, they bought as many copies as they could to have it on stock. These days you are lucky if you find that edition in a used bookstore. Dover seems to have printed way too many Prokofiev Sonatas nos.1-4 and seems to always have them on stock. You can buy them at,
www.doverpublications.comWalter Ramsey