[Stalker]

Roadside picnic
Here is the plot:
Background supposition: extra-terrestrials have apparently visited earth (possibly for a picnic as later in the book some scientist sets out in his hypothesis) and left behind many unusual items, of which the earthlings have little or no clue of their origin or intended purpose. The items become hot commodities, and despite the danger in retrieving them from "The Zone", a massive black market arises, enough to propel the lives of the characters in the story.

The plot mostly traces the life of one "stalker", Red Schuhart, who goes after this stuff at various periods over several years. Indeed, the real meat of the book is the discussion of issues about life and freedom expressed indirectly through tracing the development of the lead characters. The book is not really a typical sci-fi thriller that entertains with weird beings, strange places, and made-up gimmicks (although there are many weird places in the Zone brilliantly described). Rather, this is a thought-provoking probe of a (to Anglo-American reader) foreign way of living and a controlling society that governs everyday social interaction. That the authors could pull this off 30-some years ago, in a tightly censored environment, makes the book all the more amazing. For sure not a light reading session, "Roadside Picnic" may not entertain as much as some might like, particularly with the fairly abrupt ending, but insight into the human condition awaits.

Remember also "Stalker" by Andrei Tarkovsky. The original scenario was alo written by Strugatsky but they took away all events going on in the book and left only the Zone and the Stalker.
I also saw several English editions of the book in Amazon.com