Wang, Gao, Trung Phan V, Shengkai Li, Michael Wombacher, Junle Qu, Yan Peng, Guo Chen, et al. (2021) 2021. “Emergent Field-Driven Robot Swarm States.”. Physical Review Letters 126 (10): 108002. doi:10.1103/PhysRevLett.126.108002.