Dimov, Stefan SGEM 2014. Nano, Bio and Green - Technologies for a Sustainable Future : 14th GeoConference. Vol. II. Conference proceedings.17-26 June, 2014 Albena, Bulgaria. -- 1. vyd. -- Sofia : SGEM, 2014. -- 721 P. -- ISBN : 978-619-7105-21-6. Gupta, R