| Autori | Titlu | Publicatia | An aparitie |
| OPREAN C., KIFOR C., OPREAN CRISTINA | A PROCESS APPROACH FOR THE ENVIRONMENT MANAGEMENT SYSTEMS | VOLUM CONFERINTA MONTREAL | 2001 |
| OPREAN C, KIFOR C. | ELECTRICAL DISCHARGE MACHINING OF SMART MATERIAL PARTS | VOLUM CONFERINTA UNIV. SAPIENZA, ITALIA | 1998 |
| OPREAN. C., KIFOR, C. | IMPLEMENTING QUALITY SYSTEMS IN ELECTRICAL ENERGY DISTRIBUTION | VOLUM CONFERINTA UNIV. SEVASTOPOL | 2001 |