Day 128: Common knowledge does not need a reference.
Although we recommend providing references for new or controversial information, we do not recommend providing references for common or widely accepted knowledge. We also do not recommend providing a reference for commonly accepted definitions or descriptions.
For example, you do not need to provide a reference for this information: “Clouds are formed from water molecules.” This is common knowledge.
You also would not need a reference for this information: “Books are composed of bound papers, which often contain words or images.”
Basically, if your readers already know, understand, and believe the information, you will not need a reference.
