1. Apostolov, A. M., L. Alberca, and D. Altidill, Solar cycle and seasonal behaviour of quasi-two- and five-day oscillations in the time variations of f0F2, Ann. Di Geofisica, 37, 187–192, 1994.
2. Barlier, F., C. Berger, J. L. Falin, G. Kockarts, and G. Thuillier, A thermospheric model based on satellite drag data, Ann. Geophys., 34, 9–24, 1978.
3. Bowman, G. G., Latitude dependence of the time delay in spread-F occurrence following geomagnetic activity, J. Atmos. Terr. Phys., 41, 999–1004, 1979.
4. Bowman, G. G., Spread-F occurrence in mid- and low-latitude regions related to various levels of geomagnetic activity, J. Atmos. Terr. Phys., 44, 585–589, 1982.
5. Bowman, G. G., A review of some recent work on mid-latitude spread-F occurrence as detected by ionosondes, J. Geomag. Geoelectr., 42, 109–138, 1990.