Nikitin, O., Väli, E., Sabanov, S., & Pastarus, J.-R. (2007). THE SURFACE MINER SUSTAINABLE TECHNOLOGY INTRODUCTION FOR OIL-SHALE MINING IN ESTONIA. ENVIRONMENT. TECHNOLOGIES. RESOURCES. Proceedings of the International Scientific and Practical Conference, 1, 55-61. https://doi.org/10.17770/etr2007vol1.1735