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Pages from this blog, our reference pages and lesson plan pages, and other informational pages on the site have been cited in a variety of forms, from wikipedia pages to scholarly dissertations. Most people aren't thinking about formal citations - they just want to link to our pages (and we welcome that), but we do occasionally get requests for the proper way to attribute information quoted on this site. Here is the proper citation method.

If the publication date and author of the page are displayed on the page, you will cite the page like this:

{Author's name} ({date}). {Page title} [{content type}]. Retrieved from {URL}.

For example, if you wanted to cite the post on this blog about the force of gravity in a spherical shell, it would look like this:

Twitchell, Douglas (2016, Nov 29). Force of Gravity in a Spherical Shell [blog post]. Retrieved from

Note that all blog posts on the "Ask Professor Puzzler" blog have the same author. You can find the date the article was posted under the article title. Also note, that for online citations, URLs should be in the form of a clickable link to the page you found the content.

Many pages, do not have a publication date. If that's the case, you can simply skip that item:

{Author's name}. {Page title} [{content type}]. Retrieved from {URL}.

Twitchell, Douglas. Blue Whale Eating Krill [article]. Retrieved from

And, most common of all, there is neither an author nor a publication date. Many of the lesson plans and reference units posted on this site were written by teachers and other educators who provided us only an e-mail address and/or screen name. In this case, you begin with the title.

If you want to cite something on this site, you don't need to ask permission first. However, we'd love to know about how our content is being referenced, so we'd be glad to hear from you about it, if you wanted to drop us a note. You may use the Ask Professor Puzzler form to do so.

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