Kozma, Á., Petuškova, J., Lehmann, C. W., & Alcarazo, M. (2013). Synthesis, structure and reactivity of cyclopropenyl-1-ylidene stabilized S(II), Se(II) and Te(II) mono- and dications. Chemical Communications, 49, 4145-4147. doi:10.1039/C2CC36225B.