Help: Mur ABC: values of Ex(imin), Ex(imax), Ey(jmin), Ey(jmax), Ez(kmin), Ez(kmax)?

I am trying to implement MUR boundary in the FDTD code.

In Mur boundary (from the textbooks / other papers) I got equations for tangential fields of electric field components at the boundaries. That means I got equations for

Ex(jmin), Ex(jmax), Ex(kmin), Ex(kmax),
Ey(imin), Ey(imax), Ey(kmin), Ey(kmax),
Ez(imin), Ez(imax), Ez(jmin), Ez(jmax).

But what about the remaining boundaries? What values or equations should I use for Ex(imin), Ex(imax), Ey(jmin), Ey(jmax), Ez(kmin), Ez(kmax)?
Please help me implement Mur boundary condition.

http://www.engr.uky.edu/~gedney/cour...624_Notes6.pdf,

This is the best material while I am learning ABC in FDTD.