This local source record summarizes "USSR media report: multitude of UFO sightings", published or preserved by CIA reading-room record / Blue Book Files mirror.
The declassified U.S. record summarizes Soviet press coverage that included the January 1986 event on Hill 611 near Dalnegorsk and later investigation claims.
It is an intelligence summary of foreign media, not a laboratory report or chain-of-custody record for the claimed material samples.