Electrodymanics of Moving Continuous Media with Toroid Polarization
  With regard to the toroid contributions, a modified system of equations of electrodynamics moving continuous media has been obtained. Alternative formalisms to introduce the toroid moment contributions in the equations of electromagnetism has been worked out. The two four-potential formalism has been developed for the electromagnetic continous media subjected to Lorentz transformations. 
V.M. Dubovik and B. Saha