Integrated energy return on investment calculation model. Case study of oil shale derived motor fuel production industryGušča, Julija; Eldermann, Meelis; Siirde, AndresProceedings of the 2nd International Conference on Energy & Environment: Bringing Together Engineering and Economics2015 / 286-292 Relationships between fuel prices and price indices in EstoniaKoljajeva, Irina; Iorina, PolinaIX all-Russian Scientific-Practical Conference with International Participation "Contemporary Problems of Regional Economy Management' 2012" : selected papers2012 / p. 159-163 : ill