Harmonic Superspaces For Three-Dimensional Theories
  Three-dimensional field theories with N=3 and N=4 supersymmetries are considered in the framework of the harmonic-superspace approach. Analytic superspaces of these supersymmetries are similar; however, the geometry of gauge theories with the manifest N=3 is richer and admits construction of the topological mass term. 
B.M. Zupnik