万国著作権条約
The Soviet Union did not have international copyright relations until 1973, when it joined the 1971 Paris version of the Universal Copyright Convention. This meant that when "The Secret of the Deserted Castle" was published in 1982, it was automatically copyrighted in the United States. However, the UCC did not work retroactively, so Volkov's first five works were not copyrighted in the US.