@Article{angeo-15-1271-1997,
AUTHOR = {Rangarajan, G. K. and Iyemori, T.},
TITLE = {Time variations of geomagnetic activity indices Kp and Ap: an update},
JOURNAL = {Annales Geophysicae},
VOLUME = {15},
YEAR = {1997},
NUMBER = {10},
PAGES = {1271--1290},
URL = {https://angeo.copernicus.org/articles/15/1271/1997/},
DOI = {10.1007/s00585-997-1271-z}
}