Chen G.Y., Mazurov V.D., Shi W.J., Vasil'ev A.V., Zhurtov A.Kh., “Recognition of the finite almost simple groups PGL(2)(q) by their spectrum”, Journal of Group Theory, 10:1 (2007), 71–85
А. В. Васильев, “О связи между строением конечной группы и свойствами ее графа простых чисел”, Сиб. матем. журн., 46:3 (2005), 511–522 ; A. V. Vasil'ev, “On connection between the structure of a finite group and the properties of Its prime graph”, Siberian Math. J., 46:3 (2005), 396–404