Here is a table that will help you understand. And the answer.
Ok bro, this is 2 but like i speak english
The total number of articles is 14 and only 7 can be published. Since what is asked is the ways to assemble the 7 articles, this is a permutation problem.
14P7 = <span>17297280 ways
If order is not of concern, the problem is just a combination problem
14C7 = </span><span>3432 ways</span><span />