Hierarchy of sources

All sources are not the same and just because it is in a book or on the web does not make it true or trustworthy. Sources preferred as answers are in the following order of preference

1. Peer reviewed journal articles - get from https://scholar.google.com/
2. Government reports
3. News stories
4. NPO reports
5. patents
6. the web

Format for web reference

Author Surname, Author Initial. (Year Published). Title. [online] Available at: http://web.archive.org/web/20180811212301/http://www3.website/ URL [Accessed Date Accessed].

You can export Harvard style references from Google Scholar and from Zotero.

Example

Question: How much PV is expected to be installed in the US in 2016?

• 14.5GW
  • Solar Energy Industry Association. (2016). Solar Industry Data. [online] Available at: http://www.seia.org/research-resources/solar-industry-data [Accessed July 31, 2016].

Note the answer is in an incomplete sentence with a properly formatted reference after the data. Harvard Reference style preferred with a direct hyperlink to the data.