A primary source for the article would be interviewing one of the school's board members and quote them in the article. A secondary source would be to analyze the students at the school and what they're wearing. After analyzing what the students wear, you can interpret why the board made the decision to enforce a dress code. These sources would be good to use because the article would include primary quotes as well as a reason why the school board may be enforcing a dress code.
In other words, there should be three independent resources confirming each pieces of questionable data. This cross-checking can be done different ways.
the poet insists that we should always be truthful whatever we say. ... lies in its own countrymen and countrymen can do prgress only by saying the truth.