Web Site Citation-No Page Number

For web site sources that do not provide page numbers, the abbreviation "para". If neither paragraph nor page numbers are visible, cite the heading and the number of the paragraph following it to direct the reader to the location of the material.   

(Butler, 2006, Conclusion section, para. 1)

Web Site Citation-No Author/Date

If a web page does not indicate the name of the author(s), refer to the document by repeating the first few words of its title. Example: (“Study finds,” 2001). If the information being referred to appears on an untitled Web page, indicate in the text of your paper where the reader is to look if he or she wishes to find a full reference to the Web site that contains that page. If no date is available, use n.d. (no date).

Example:

More companies today are using data mining to unlock hidden value in their data. The data mining program “Clementine,” described at the SPSS Web site, helps organizations predict market share and detect possible fraud (SPSS, n.d.).

Readers of the preceding example will know to look for the complete citation under "SPSS" in the "References" section.