@article{SIGMA_2012_8_a44,
     author = {Jen-Chi Lee and Catherine H. Yan and Yi Yang},
     title = {High-energy string scattering amplitudes and signless {Stirling} number identity},
     journal = {Symmetry, integrability and geometry: methods and applications},
     year = {2012},
     volume = {8},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SIGMA_2012_8_a44/}
}