Brandhuber, A., Heslop, P., Travaglini, G., & Young, D. (2015). Yangian Symmetry of Scattering Amplitudes and the Dilatation Operator in N=4 Supersymmetric Yang-Mills Theory. Physical Review Letters, 115(14), Article 141602. https://doi.org/10.1103/physrevlett.115.141602