TIMČÁK, Gejza, 		JABLONSKÁ, Jana, 		MIXTAJ, Ladislav, 		ŠTRBA, Ľubomír, 		DERCO, Ján, AND 		WEISS, Erik.
" Ecological Thinking and Certification of Hotel Service Providers in Slovakia" <em>Journal of Environmental Management and Tourism</em> [Online], Volume 7 Number 2 (14 November 2016)