@article{10_4153_S0008439519000067,
     author = {Huang, Libing and Shen, Zhongmin},
     title = {Homogeneous {Einstein} {Manifolds} with {Vanishing} $S$ {Curvature}},
     journal = {Canadian mathematical bulletin},
     pages = {525--537},
     year = {2019},
     volume = {62},
     number = {3},
     doi = {10.4153/S0008439519000067},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/S0008439519000067/}
}