Costello, C., & Sharma, M. (2012). Elgg 1.8 social networking: Create, customize, and deploy your very own social networking site with Elgg (2nd ed.). Packt Pub..

Costello, Cash, and Mayank Sharma. Elgg 1.8 Social Networking: Create, Customize, and Deploy Your Very Own Social Networking Site with Elgg. 2nd ed. Birmingham, U.K.: Packt Pub., 2012.

Costello, Cash, and Mayank Sharma. Elgg 1.8 Social Networking: Create, Customize, and Deploy Your Very Own Social Networking Site with Elgg. 2nd ed. Packt Pub., 2012.