00520naa#a2200181#i#450# EN\RIOR\bibl\5823 20240503005010.5 2409-6024 20141230b2014####ek#y0engy0150####ca RUS RU Real options method in the assessment of mining industry investment Journal article Moscow Publishing Center RIOR 2014 7 с. Journal article local Gusev Andrey Alekseevich Narulin Denis riorpub.com