Reinik J., Heinmaa I., Ritamäki J., Boström D., Pongrácz E., Huuhtanen M., Larsson W., Keiski R., Kordás K., Mikkola J.-P. Direct CO2 sequestration onto alkaline modified oil shale fly ash. 2014. Oil Shale. 31. 1. 79-90. 10.3176/oil.2014.1.08.