M. P. Johansson, J. Juselius. Arsole Aromaticity Revisited. Lett. Org. Chem. 2005, 2: 469–474. doi:10.2174/1570178054405968.
A. Muranaka, S. Yasuike, C-Y. Liu, J. Kurita, N. Kakusawa, T. Tsuchiya, M. Okuda, N. Kobayashi, Y. Matsumoto, K. Yoshida, D. Hashizume, M. Uchiyama. Effect of Periodic Replacement of the Heteroatom on the Spectroscopic Properties of Indole and Benzofuran Derivatives. J. Phys. Chem. A. 2009, 113 (2): 464–473. doi:10.1021/jp8079843.