The Joint Accelerator Conferences Website (JACoW) is an international collaboration that publishes the proceedings of accelerator conferences held around the world.
Y.K. Wu et al., “Generating Orbital Angular Momentum Beams in an FEL Oscillator”, presented at the 39th Free Electron Laser Conf. (FEL'19), Hamburg, Germany, Aug. 2019, paper TUD01, unpublished.