1. https://portal.eiscat.se/schedule/comment.cgi?fileName=20211214124973&Start=0000&End=0600
2. A New Method for Research on Magnetically Oriented Ionospheric Inhomogeneities using a Program of Radio-System Determination
3. EISCAT observations of meteors from the sporadic complex
4. Ugarov VA Propagation and generation of low-frequency electromagnetic waves in the upper atmosphere;Gershman,1960
5. http://wdc.kugi.kyoto-u.ac.jp/igrf/point/index.htm