@book{ BA18733581, author = "URSI/COSPAR Symposium and Rawer, K. (Karl) and Piggott, W. R. and Paul, A. K.", title = "Advances in global/regional descriptions of ionospheric parameters : proceedings of URSI/COSPAR Symposium held in Athens, Greece, 1-4 October, 1991", publisher = "published for the Committee on Space Reseach by Pergamon Press, 1992", year = "1992", series = "Advances in space research", number = "vol. 13, no. 3", URL = "https://ci.nii.ac.jp/ncid/BA18733581" }