Ivkovic Ivan S,Janjos Zeljko,Danon Gradimir J,Zezelj Srecko (2014) Dynamic Friction in the Braking, Tire - Road Contact, PROCEEDINGS OF THE SECOND INTERNATIONAL CONFERENCE ON TRAFFIC AND TRANSPORT ENGINEERING (ICTTE), vol. , br. , str. 420-430 (Proceedings Paper) 

Ivkovic Ivan S,Janjos Zeljko,Milovanovic Branko M,Zezelj Srecko (2012) Fuel Consuption Analisys of Cng and Hybrid Buses on the Road Nework, PROCEEDINGS OF INTERNATIONAL CONFERENCE ON TRAFFIC AND TRANSPORT ENGINEERING (ICTTE), vol. , br. , str. 227-242 (Proceedings Paper) 

Ivkovic Ivan S,Janjos Zeljko,Zezelj Srecko,Jovanovic Vojkan D (2011) Research into the costs of vehicle exhaust gases from the standpoint of using natural gas-powered buses, AFRICAN JOURNAL OF BUSINESS MANAGEMENT, vol. 5, br. 22, str. 9304-9321 (Article) 

Petrovic Jelica M,Ivkovic Ivan S,Vujacic Ivan,Zezelj Srecko (2009) Possibilities of Buses on Alternative Fuel in Public Urban Transport in Belgrade, TECHNOLOGICAL AND ECONOMIC DEVELOPMENT OF ECONOMY, vol. 15, br. 1, str. 78-89 (Article) 

Petrovic Jelica M,Ivkovic Ivan S,Vujacic Ivan,Zezelj Srecko (2008) Environmental and economic effects of natural gas and biodiesel buses in public urban transport - the case of Belgrade, 7TH INTERNATIONAL CONFERENCE ENVIRONMENTAL ENGINEERING, VOLS 1-3, vol. , br. , str. 1020-1026 (Proceedings Paper) 

Petrovic Jelica M,Glumac Stanislav,Vujacic Ivan,Zezelj Srecko (2001) Effects of privatization of public urban transport - the case of Beograd, URBAN TRANSPORT VII: URBAN TRANSPORT AND THE ENVIRONMENT IN THE 21ST CENTURY, vol. 8, br. , str. 259-267 (Proceedings Paper)