ENVIRONMENT. TECHNOLOGIES. RESOURCES. Proceedings of the International Scientific and Practical Conference; Vol 1 (2001): Environment. Technology. Resources. Proceedings of the 3rd International Scientific and Practical Conference; 173-181 Environment. Technology. Resources. Proceedings of the International Scientific and Practical Conference; Vol 1 (2001): Environment. Technology. Resources. Proceedings of the 3rd International Scientific and Practical Conference; 173-181