TY - JOUR A1 - Danilov, A. D. A1 - Mikhailov, A. V. T1 - Letter to the Editor: Spatial and seasonal variations of the foF2 long-term trends JO - Ann. Geophys. J1 - ANGEO VL - 17 IS - 9 SP - 1239 EP - 1243 Y1 - 1999/09/30 PB - Springer Verlag SN - 1432-0576 UR - https://angeo.copernicus.org/articles/17/1239/1999/ L1 - https://angeo.copernicus.org/articles/17/1239/1999/angeo-17-1239-1999.pdf DO - 10.1007/s00585-999-1239-2 ER -