Hello. You did not quote the article to which the question refers, which makes it impossible to answer. However, I can help you by showing you how the authors develop the central idea of your articles, so I can direct you to find the answer in the text you have.
The authors develop the central ideas of their articles through evidence that they found in another text, presenting quotes, or even removing evidence from facts confirmed by statistics, calculations, numbers or situations witnessed by the author himself.
When the author presents quotes from another text, he uses the opinion of an expert to confirm the point of view that the author wants to present in the article. The same can be seen with the presentation of statistical results, where the author uses numbers and mathematical proof to confirm that the central idea of his text is coherent and correct.