Singular Cauchy integrals and conformal welding on Jordan curves. Nag, Subhashis — 1996 Annales Academiae Scientiarum Fennicae. Series A I. Mathematica
On the tangent space to the universal Teichmüller space. Nag, Subhashis — 1993 Annales Academiae Scientiarum Fennicae. Series A I. Mathematica