You need to give credit to sources for several reasons:

• To let your readers know how your views, "agree with, disagree with, or modify the views of published experts in the field."

• By citing your sources, you are providing your reader with additional information--such as books, articles, and websites
  --on the topic you are writing about.

• "By listing the author of a quotation and providing a page number, you're telling the reader, 'If you don't believe that this person really wrote this, you can look it up for yourself.'"

• "It's the honest thing to do."

Source: Plagiarism (Microsoft Word document) - UWGB Writing Center handout

In the case of EBMgt, it also supports and gives credence to your evidence based sources.