Nakagawa, H., Kasaba, Y., Maezawa, H., Hashimoto, A., Sagawa, H., Murata, I., et al. (2009). Search of SO2 in the Martian atmosphere by ground-based submillimeter observation. Planetary and Space Science, 57(14-15), 2123-2127. doi:10.1016/j.pss.2009.10.001.