List of Articles Negative data Open Access Article Abstract Page Full-Text 1 - Efficiency Evaluation in Presence of Undesirable and Negative Factors Mahnaz Maghbouli Mahdi Eini Farhad Taher 20.1001.1.25885723.2020.12.2.9.7 Open Access Article Abstract Page Full-Text 2 - A Bounded Additive Model for Efficiency Evaluation in Two-Stage Production Systems With Negative Data Hamidreza Babaei Asil Reza Kazemi Matin Mohsen Khounsiavash Zohreh Moghaddas Open Access Article Abstract Page Full-Text 3 - Upgrading inefficient decision making units (with negative data) towards common weights (using DEA) Hossein Abbasiyan 20.1001.1.25885723.2021.13.3.1.8 Open Access Article Abstract Page Full-Text 4 - Efficiency Evaluation of Economic Enterprise in Presence of Interval Undesirable and Negative Data Mahnaz Maghbouli Mahdi Eini Farhad Taher Fatemeh Ghomanjani