941 20220928155318.0 10.1016/j.asr.2010.07.017 DOI SIDCimport-1132 Stankov, S. M. 2010 Seasonal variations of storm-time TEC at European middle latitudes STCE Stegen, K. Warnant, R. 1318-1325 10 Advances in Space Research 46 2010 published in REFERD