TY JOUR TI On calculation of rotation of vector fields using the formula POINCARE KW vector field KW Poincare´s formula JO Actual directions of scientific researches of the XXI century: theory and practice AU Tsymbalova, O.. PY 2014 IS 2 PB FSBE Institution of Higher Education Voronezh State University of Forestry and Technologies named after G.F. Morozov