look in a library, perhaps a university library would be better since they would have more books and articles available.
I do not know any evidence offhand, but look into the bleepinator (the nickname given to the infamous bleeping of profane language in tv), the cause of that and the effects of it. Look for specific television stations differing standards, and their motives. I know FOX and MTV have much lower standards than say, NBC.
Look for marks in the history of it all and the reactions that incurred from each mark. I recall a famous line from a movie i think is Gone with the Wind in which a character states as one of, maybe the, final line of the movie: "Frankly, my dear, i don't give a damn." I remember that was a controversy regarding the word damn and the producers of the show knew it but risked it even when the word damn would previously not be allowed on television before.
Also, ratings in movies help to get around this mess. They can tag on higher ratings and allow more intense language, and now they do it with TV. They have ratings on TV shows now shown in the top left corner of the screen. Then there is the advent of the V-chip where parents can block shows that have displeasing violence/language/sexual scenes.
If you need information on affirmative ideas in regards to this topic, you could very well look into general censorship literature for a start. There should be a lot of literature on this topic. Really.
Long messages do not equal aggravation of any sort,
rather they reflect nothing more than a response of insight
that should always be read in a matter-of-fact tone.
"Those womyn that seek equality with men, lack determination."
"I beseech you, in the bowels of Christ, think it possible you may be wrong."