1. dr Ernesto Hontoria (2016) "USE A TWO STAGE ANAEROBIC DIGESTOR TO IMPROVE THE CONVENTIONAL MESOPHILIC ANAEROBIC DIGESTION PROCESS" - XI Savjetovanje hemičara, tehnologa i ekologa Republike Srpske
(https://ekonferencije.com/bs/rad/use-a-two-stage-anaerobic-dige/4477)