"Books are engines of change,windows on the world, and (as a poet has said) “lighthouses erected in the sea of time.” They are companions, teachers, magicians, bankers of the treasures of the mind. Books are humanity in print."
...includes "new media exposure" in its header-description, so that one would be the most appropriate, but people have sometimes posted such things in Chit-Chat as well (and/or in the language-specific forums if the article was in a language other than English).
That may not help with your search - the forum-search is a bit fussy, and can leave out hits due to differences in spacing or punctuation from the search-string, among other things.
You could go ahead and post the reference yourself, with a note that it may have been mentioned before. After 4 years I don't think anyone would mind another mention!