Sumaruk, T., and P. Sumaruk. “Reflection of the Solar Activity Hale Cycles on the Geomagnetic Field Secular Variations”. Geofizicheskiy Zhurnal, vol. 42, no. 5, Nov. 2020, pp. 183-92, doi:10.24028/gzh.0203-3100.v42i5.2020.215081.