Sources
A source is anything that someone else has written that has directly contributed to what you have written. To cite a source (cite spelled C-I-T-E), you only need to include a "References" section near the end of your document that contains a numbered list of sources.
Each source should include: the name of the work you are citing, the name or names of the authors, the date of publication, and if possible a link to the resource. Throughout your document, if you are quoting or referencing something from one of your sources, be sure to mark the sentence or paragraph with a number that corresponds to that specific source in your reference section.
If you are ever in doubt as to whether or not you should list something as a source, the best idea is to go ahead and cite the source, as otherwise you open yourself to accusations of plagiarism, and few things will destroy your professional reputation as quickly as plagiarism. When people realize you have represented someone else's work as your own, they will not think highly of your sense of ethics, competence, and trustworthiness.
Many people think that plagiarism is only when you copy and paste someone else's work into your own, but this is only one form of plagiarism called "Direct" plagiarism, which is relatively rare in business writing, as there are many ways to get caught if all you do is copy-and-paste. Instead, much more common are "Paraphrasing" plagiarism and "Mosaic" plagiarism.
Paraphrasing plagiarism is when you copy what someone else wrote and only adjust a few words in a few places to make it seem like your own original content. Mosaic plagiarism is when you take phrases or sentences from one or more sources and scatter them throughout your writing.
Fortunately, in the business world, there is no drawback to citing credible sources, as it increases people's trust in you and your work, establishes and maintains your intellectual credibility, and demonstrates your commitment to ethical conduct. In this way, citing sources is the polar opposite of plagiarism: instead of ruining your professional reputation, it builds and enhances your professional reputation.
The question then is, how do we determine if a source is credible?
Generally, any scientific research paper that is published in a top peer-reviewed journal can be considered credible. These types of journals include, "The New England Journal of Medicine," "Journal of the American Cancer Society," and "Proceedings of the National Academy of Sciences;" among many others that all tend to be specific to a particular field of study. These journals have incredibly high standards, as scientific research teams must have their papers reviewed by other experts in the field under the supervision of the journal's editors to be approved for publication.
Of particular note is that scientific research papers themselves will always list every source that they have used in their research, usually in exhaustive detail. For example, the paper, "Evolution of antibody immunity to SARS-CoV-2" published in January of 2021 in the highly prestigious scientific journal "Nature," has a reference section listing 58 sources.
Unfortunately, once you leave the realm of the top peer-reviewed scientific research journals, determining the credibility of a source becomes increasingly more difficult.
At a minimum, a credible resource is one written by people who are credible. This requirement eliminates all books, articles, and webpages that represent nothing more than a single person's unqualified opinion, which in turn wipes out the vast majority of the internet.
This is a common pitfall in Googling for sources: the top results may lead to pages that only represent the opinion of a single person, even if the website itself seems credible. Always check to make sure who authors whatever source you are thinking about citing and verify their expertise to make sure that they are a credible author.
Even if someone is credible, an article published by them on their personal website is far less credible than if the same article is published by a prestigious institution. For example, if a lawyer were to publish a legal opinion on their personal website, it is far less credible than if exactly the same article were published in "Harvard Law Review," as the assumption would be that the editors and publishers of Harvard Law Review would not have published the lawyer's article unless they had verified its credibility.
While a lot of bad sources can be eliminated by sticking to credible authors who are published by prestigious institutions, things are still complicated if that institution has a bias towards a particular point of view. This issue comes up most frequently in conversations about a source's political bias, but any form of bias can be problematic. Ultimately, if you cite a source from an author or institution that people associate with a particular bias, your work will also inherit that bias.
A common point of confusion is the role of Wikipedia as a source. Most people would not consider Wikipedia a credible source at all, as the contents of any Wikipedia page can be edited by any anonymous person on the internet. However, well-maintained Wikipedia pages usually have copious amounts of sources listed in their References section, but each of the listed sources may or may not be a good source to use. In other words, Wikipedia itself should not be used as a source, but the reference section of a Wikipedia page might be a good starting point to find credible sources.
Citing sources is an essential component of professional writing, as it demonstrates your intellectual credibility, commitment to ethical conduct, and establishes trust with your audience. Failing to cite sources can result in accusations of plagiarism and quickly ruin your professional reputation.
Even if you are under immense pressure to meet a deadline, provided you are writing something that represents you as a professional - which in the business world you always are - resist the temptation to copy-and-paste bits and pieces of someone else's work, and always take the time to list your sources.