The classification and curvature of biquotients of the form   $Sp(3)//Sp(1)^2$
  We show there are precisely 15 inhomogeneous biquotients of the form $Sp(3)// Sp(1)^2$ and show that at least 8 of them admit metrics of quasi-positive curvature. 
Jason DeVito, Robert DeYeso III, Michael Ruddy, Philip Wesner
math.DG