Is it illegal to spank your kids in California?

CITATIONS PLEASE?

For example, under California law,

"... a parent has the right to reasonably discipline a child by physical punishment and may administer reasonable punishment without being liable for battery. In order to be considered disciplinary the punishment must:"

Be necessary (i.e. there it must be in response to a child's negative behavior). Be reasonable, not excessive, in the judgment of a third party -- e.g. a Child Protective Services representative, or a law enforcement officer. 1