Research articles published in scholarly journals have in most cases been through a rigorous peer-review process. Other scholars have scrutinized the reasoning and methodology and decided that it meets their professional standards. This process provides a peer-reviewed article with a certain amount of authority.
When you refer to a scholarly, peer-reviewed article in your presentation, you are using that authority in the service of your own argument. This technique will help you be persuasive.
As you can see from the list below, dozens of databases are available to help you locate research in any field you choose. You might find that if your topic is in a specific field covered by one of these databases (e.g. psychology or health), it is more productive to use one of these than to use OneSearch.