Hot Paper: Enhanced whale optimization algorithm for medical feature selection: A COVID-19 case study Highly Cited Papers: Starling murmuration optimizer: A novel bio-inspired algorithm for global and engineering optimization QANA: Quantum-based avian navigation optimizer algorithm DMDE: Diversity-maintained multi-trial vector differential evolution algorithm for non-decomposition large-scale global optimization A systematic review of the whale optimization algorithm: theoretical foundation, improvements, and hybridizations Binary Approaches of Quantum-Based Avian Navigation Optimizer to Select Effective Features from High-Dimensional Medical Data B-MFO: A Binary Moth-Flame Optimization for Feature Selection from Medical Datasets GGWO: Gaze cues learning-based grey wolf optimizer and its applications for solving engineering problems MFO-SFR: An Enhanced Moth-Flame Optimization Algorithm Using an Effective Stagnation Finding and Replacing Strategy