• Selective crushing methods for oil shale mining with crushing bucketsKaru, Veiko; Rahe, Tiit; Saarnak, Martin; Lüütre, Enn; Nurme, Martin; Närep, Erki; Valgma, IngoInternational oil shale symposium : Tallinn, Estonia, June 10-13, 20132013 / p. 59-60 https://kirjandus.geoloogia.info/en/reference/34007