I am pleased that your reaction about this is curiosity. :)

The most common reaction for most people when i tell them about this, is denial, and then to refuse to do any research about it.

There is many sources to this, but the best of all sources is the news paper them self, its simply enough to see where they get their sources from whenever they write about anything that is about wars and foreign stuff, and you will pretty soon see the pattern..

Outside USA and England where the Reuters news dont need to be edited, most countries have a government controlled department that edit the Reuters "news" to fit their own existing propaganda.

Most western countries use the same propaganda, but it difference a little about certain things from country to country.
So in Norway where i live for example, it is something called NTB that does the editing of the Reuters news, so that it always fit our existing propaganda.

It would kind of be wrong if i should give you one single source for your research about this, because then it kind of would not be worth more then my words about it, since it was me that directed you to read about something i already have said, just to add credibility to my own words.

Real research will always be best when it is you that find it.
Because anyone can say almost anything, and give you a link to something that will make their words look more true.

But if you start to look at it, you will pretty soon see that same pattern in all western countries.
They all have many many different news paper, even if they all say the same things about almost everything.

In Norway for example we have 300 different newspaper, and they all write the same, even if some are left winged and other are right winged.
(This gives the people the false impression of great freedom for the press)
But in reality, they all write the same Reuters news.

For example when it comes to why we attacked Libya.
Why we attacked Syria and so on.

In the case of Ukraine for example, they all called it a people "revolution"
And not one single newspaper told the truth that it was a NATO organised "revolution"

It was the same in both cases when it comes to Libya and Syria too.
In the begining they all write that the people there had started a "revolution" even if that is a lie, and they both was victims of a highly organised NATO attack..

For the same reason they all decide what to write about and not also.
Therefore we can for example see that 3000 newspaper in USA all write about something silly Trump have said one day, and at the same time you will see that 3000 news paper are completely silent about the American attack on Yemen.. ;)

People have been fooled to believe that having a lot of different news paper is the same as a sign of freedom for the press, even if they all write the same.

If we really had freedom for the press, you would not need a license from the government to print a news paper.. ;)

I know this because i have worked for many news paper, and because i have been in prison because i printed a news paper without a license from the government.

Its the same for TV, you need a license to start a TV station too, for the same reason. Our governments demand to control what "news" the people shall get.. ;)