For more details on the available upgrades for a model, click on the references listed next to the model name.

Taking a look at the WikiPedia(*) entry for the topic the first reference listed is from 2002; so that's older than Twitter.

If you'd like to try collecting some of these, the references listed at the end of this article will help you do so safely.

For a rigorous and general proof, see Kelly's original paper or some of the other references listed below.

A photograph of George R Smith College, with students, can be found among the references listed here.

All awards except the Loncin prize have this reference listed below.

The cultural references listed below are separated into categories, such as novels, comics, anime and manga, games, television, music and others.

Along with the references listed below, Griswold (2001) cites several additional articles on her work.

Possibilities include regulating sodium appetite and arousal, and are discussed in several of the references listed below.

This article incorporates text from the references listed below, publications now in the public domain.