Spectroscopic observations of propagating disturbances in a polar coronal hole: evidence of slow magneto-acoustic wavesG. R. Gupta, L. Teriaca, E. Marsch, S. K. Solanki and D. BanerjeeA&A, 546 (2012) A93DOI: https://doi.org/10.1051/0004-6361/201219795
