Dic: touch (up)on something

• The film touches on these issues, but only superficially.
• The teacher only touched upon the subject. There wasn't time to do more than that.
• During the interview, we only touched on how much I would be paid.

VERB | If you touch on a particular subject or problem, you mention it or write briefly about it.

cf. touch on something: to be connected to.

• Although his book is about an event of many years ago, it touches on similar events of today.

.... Cobuild, http://idioms.thefreedictionary.com/touch+on