"has touched upon" is correct and usable in written English.
You can use this phrase when you want to mention a particular topic or subject in passing. For example, "His speech has touched upon the difficulties of maintaining a healthy lifestyle."
Patricia Brooks has touched upon a much bigger issue than our personal comfort in her article on noisy restaurants ("To Din or Not to Din: Restaurateur's Call," July 16).
It's sharpened too by a few fleeting moments of compassion, like this brief description of a toilet attendant caught up in the murder investigation: "trembling upon the event which has touched upon her life without the asking".
At the same time as opponents of equal marriage set out their stall at Conservative party conference, Young has touched upon something that is incredibly common among LGBT people – internalised shame.
Woody Allen has touched upon the notion of guilt before, in his heavy-going London drama Match Point, but most importantly in his wonderful Crimes And Misdemeanors, in which the crime is genuinely shocking.
The keynote of the book is the presentation of the main features of plant form from the viewpoint of function, and the author has touched upon various matters not usually discussed in works of this limited size, instead of simply going over ground already covered in numerous books of this scope.
But what Fairbairn has touched upon is something I've thought for a while: that face-showing has its place in small doses, but what is important is a prolific body of work, a good reputation and good people skills during a brief chat over coffee; that it is possible to rise to the top of the ladder while, like Fairbairn, leaving parties early to cuddle your children.
But Mr Bush, wittingly or not, had touched upon a serious point.
An open question is therefore how the various mechanisms we have touched upon could be better unified to help developers configure, compose, and extend existing platforms, and take informed decisions on how best to obtain desired features.
The solution is true media personalisation, and it doesn't just solve the identification and quality problems I've touched upon above.
STEINHARDT -- I don't think we've touched upon what might happen.
Jamie: At the same time, we've touched upon things you're not 'supposed' to touch upon.
