"Long Live the Animated Gif: A Study on the Curation, Acquisition, and Preservation of Animated GIFs" by Small Data Industries. 2018. Article.
Excellent historical overview and technical breakdown of GIF format, based on extended interviews, research, and collections consultations at the Museum of the Moving Image.
https://web.archive.org/web/20200520211628/https://opensource.smalldata.industries/research/gif/
"Mass Effect" by Lauren Cornell and Ed Halter (eds). 2015. Book.
Edited anthology that attempts collection of key currents, arguments, and conditions related to dynamics between art and the internet. Featuring an array of informal and alternative discussions, web-chat transcripts, and creative articles by significant contemporary net artists and critics, the fun and weighty tome is a fine introduction to many recurring issues and central players.
"Digital Folklore" by Olia Lialina and Dragan Espenschied (eds). 2009. Book.
Landmark edited compendium of primary sources and user-generated accounts of net art. Indispensable and wonderfully designed, you should definitely have this book on-hand if working with legacy internet materials.