Twistor Space Structure of the Box Coefficients of N=1 One-loop   Amplitudes
  We examine the coefficients of the box functions in N=1 supersymmetric one-loop amplitudes. We present the box coefficients for all six point N=1 amplitudes and certain all $n$ example coefficients. We find for ``next-to MHV'' amplitudes that these box coefficients have coplanar support in twistor space. 
Steven J. Bidder, N.E.J. Bjerrum-Bohr, David C. Dunbar and Warren B.   Perkins