I always recommend Ross Greene's CPS: www.livesinthebalance.org
The Explosive Child (recently revised, in a 2014 edition)

And I would start to look for any kind of pattern. Think of behavior as communicative, and try to find the "message".

Under what conditions are these incidents occurring? at certain times of day? on certain days of the week? after particular activities? when hungry? tired? after a busy day? a disruption in routine? for certain task-types? has she recently undergone any changes in her life situation or those of key figures in her life?

What does she get out of an episode? escaping work? your attention (either related or unrelated to instruction)? a neurotransmitter rush?

...pronounced like the long vowel and first letter of the alphabet...