Self-Duality in 3+3 Dimensions and the KP Equation
  We consider two types of generalized self-duality conditions for Yang-Mills fields on paracomplex manifolds of arbitrary dimension. We then specialize to $3+3$ dimensions and show how one can obtain the KP equation from these self-duality conditions on $SL(2,R)$ valued gauge fields. 
A. Das, E. Sezgin and Z. Khviengia