On the effect of the Earth's magnetic field on the crop-producing power of winter wheat in the territory of Ukraine - A. V. Kendzera; O. E. Starovojt; V. D. Omelchenko; L. I. Nadezhka; Ju. M. Volfman; I. P. Gabsatarov; S. P. Pivovarov; Ju. V. Lesovoj (Geophysical journal, 2012)