Question on resilience

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?

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