When no author is provided, use the title of the source in place of the author's name in the references list. Follow MLA rules for capitalization and formatting, depending on the type of source. List the entry alphabetically by the first word in the title:
Works Cited
"Childhood trauma." Trauma Survivors. 12 Dec. 2010. http://trauma-survivors.org/resources/childhood-trauma.htm
In-text Citation
("Childhood trauma").