I recently ran across a reference to the fantastic Russian Sci-Fi classic Roadside Picnic by Arkady and Boris Strugatsky that included a link to a free online version of the novel. You can read or download the book here.

The Strugatsky brothers were strongly influence by Stanisław Lem but later they went on to develop their own, unique style of science fiction writing that emerged from the period of Soviet rationalism in Soviet literature and evolved into novels interpreted as works of social criticism. Their best-known novel, Piknik na obochine, has been translated into English as Roadside Picnic.

“Roadside Picnic is a “first contact” story with a difference. Aliens have visited the Earth and gone away again, leaving behind them several landing areas (now called the Zones) littered with their refuse. The picnickers have
gone; the pack rats, wary but curious, approach the crumpled bits of cellophane, the glittering pull tabs from beer cans, and try to carry them the glittering pull tabs from beer cans, and try to carry them home to their holes.
Most of the mystifying debris is extremely dangerous. Some proves useful—eternal batteries that power automobiles—but the scientists never know if they are using the devices for their proper purposes or employing (as it were) Geiger counters as hand axes and electronic components as nose rings. They cannot figure out the principles of the artifacts, the science
behind them. An international Institute sponsors research. A black market flourishes; “stalkers” enter the forbidden Zones and, at risk of various kinds of ghastly disfigurement and death, steal bits of alien litter, bring the stuff out, and sell it, sometimes to the Institute itself.” from Ursula K. Le Guin’s forward to the 1977 U.S. edition.

All in all, a great read for a hot summer day.