Yeah except Roadside Picnic was published in 1972 and basically invented the term.
From wikipedia:
The term "stalker" became a part of the Russian language and according to the authors, became the most popular of their neologisms. In the book, a stalker is a person who breaks the prohibition, enters the Zone and takes out artifacts from it, which they sell as a living. In Russian, after Tarkovsky's film, the term acquired the meaning of a guide who navigates forbidden and uncharted territories; later on, fans of industrial tourism, especially those visiting abandoned sites and ghost towns, were also called stalkers.
