WotLK Question on resilience

[Xxanarg]

In its tooltip, resilience provides 3 benefits:

1. Reduced chance to be crit by players
2. Reduced crit damage and mana burns
3. Additional damage reduction from players

I'd like to as how points 2 and 3 interact with each other and other damage reduction effects.

Do points 2 and 3 stack additively or multiplicatively?

E.g.: At 1325 resi, the tooltip says 30.92% reduction of critical strike dmg and 28.11% of additional damage reduction.
Are those 2 figures totaled up to 59.03% (additive) total damage reduction from player crits?
Or 39.61% (multiplicatively, if my math is correct)?

Furthermore, how does the damage reduction in point 3 stack with other damage reduction effects such as Ele Shaman's Astral Shift?
Again, do you add the damage reduction additively to the above figure from resi or multiplicatively?

[skullatbash]

multiplicatively

you can easily test by applying a dot which is able to crit on a players with resilience.
Check the difference between the not-crit tick and the crit ones