You don't seem to have attached an image, but ...
If I remember correctly, a Ferguson's formulation was similar to Coon's in that he had the end points and the tangents. So there were 4 variables:
- P0 - start point
- P1 - end point
- T0 - start tangent
- T1 - end tangent
Where Bézier used 4 control points:
- C1 - start point
- C2
- C3
- C4 - end point
So to convert from Ferguson to Bézier, you do the following:
c1 = P0;
c4 = P1;
C2 = P0 + T0;
C3 = P1 - T1;
But my memory might be a bit faulty. I haven't read Ferguson's paper in a very long time.
I also did this other post about converting between different spline representations, but that was for 2D parametric surfaces rather than 1D parametric curves, so you might find it more confusing than helpful.