List of Articles Undesirable outputs. Open Access Article Abstract Page Full-Text 1 - An inverse DEA approach in the presence of undesirable outputs based on the directional distance function Javad Gerami Open Access Article Abstract Page Full-Text 2 - Fixed cost allocation in two-stage system in the presence of undesirable outputs Leila Emami Farhad Hosseinzadeh Lotfi Mohsen Rostamy