List of Articles Requirements Elicitation Open Access Article Abstract Page Full-Text 1 - Requirements Engineering Model in Designing Complex Systems Farhad Zivari Khorsand Rassoul Noorossana Jafar Gheidar Kheljani Open Access Article Abstract Page Full-Text 2 - Requirements Engineering Model in Designing Complex Systems Farhad Zivari- Khorsand Rassoul Noorossana Jafar Gheidar-Kheljani