Kola Superdeep Borehole - Soviet scientific deep drilling project.docx - Kola Superdeep Borehole - Soviet scientific deep drilling project University of | Course Hero
In order to reach the diamonds located 90-150 miles below Earth's surface, how would a digging program look like? What technology would it require? - Quora
Why Did the Russians Seal Up the Kola Superdeep Borehole? | HowStuffWorks