Juana has given the correct response. To explain further - the links given to an external site should be such that they are not promotional in nature (known as spamming). Thus, for example, if I write an article on how to sell a product at a reputed e-commerce site, I can give a link to its policy page, but cannot give a link to any product page. You must also ensure that external links are to reputed sites. For example, I can give links to universities, schools and colleges, but not to a tuition class.
It is also a good idea to give internal links as it will keep the readers within the pages of ISC. Thus, in a college admissions article I would give a link to the college page.of ISC and could give the external link to the college website at the end, where the contact details are mentioned.
When people come at you with their worst, you should come at them with your best (advice given to Selena Gomez by her mother, quoted in Time magazine.)