References include the following items:
- a (permanent) reference (e.g. the book title and author, or the article title and date and journal name and volume, etc.)
- a web link, where possible
- a pointer to the page or section
- a quote of the relevant text, to protect against link-rot and to aid the reader who doesn't want to search further
- an indication of your opinion on the reliability of the source, and why.
This answer is based on an answer from What constitutes a reference?What constitutes a reference?