Relationship between DEA models without explicit inputs and DEA-R models -- Finding efficient surfaces in DEA-R models -- Cost and revenue efficiency in DEA-R models -- A Novel Slack-Based Model for Efficiency and Super-efficiency in DEA-R -- A Multi-Criteria Ratio-Based Approach for Two-Stage Data Envelopment Analysis -- A novel network DEA-R model for evaluating hospital services supply chain performance -- A novel inverse DEA-R model for inputs/output estimation -- Evaluation of Two-Stage Networks based on Average Efficiency Using DEA and DEA-R with Fuzzy Data -- Stochastic network DEA-R models for two-stage systems.