One of the newer style formats, ASA style was created by the American Sociological Association starting in 1992, finally being published in 1996.  This style "...provides guidance for writing, submitting, editing, and copyediting manuscripts for ASA journals and other publications that follow ASA’s style. The newest edition includes expanded information on the use of electronic, digital, and social media sources, as well as guidance for online manuscript submissions."  Similar to Chicago's 'author-date' format.

ASA format uses the author-date method:

• When to add page numbers:
  • When direct quoting
  • When paraphrasing a passage
  • When you refer to a specific passage
• If you use a ' signal phrase' (mention the author's name in the text), just put the date in parentheses directly after the name
• Mentioned author in the text, and did a direct quote?  In-text citation looks like this:  (Year:Page#) - no space after the colon
• If you don't have the author's name in the text, you have to have the name and date in parentheses: (LastName Year) - just a space between name and year; no comma
• More than One Author:
  • Two: Use both past names:  (Name and Name Year)
  • Three: First time you cite: (Name, Name, and Name Year)
    • Next time you cite the same one: (Name et al. Year
  • Four +: Just use (FirstAuithorLastName et al. Year) for all
• No Author?
  • Take info. from the complete reference that will let a reader find that specific reference:  (InstitutionName Year:Page#)

Books

• One Author:
  • Author's full name, inverted so that last name appears first. Year. Book Title in Title Caps and Italicized. Publishing City: Publisher.
• Two + Authors:
  • Same as with one, except don't invert authors names after the first one: Lastname, Firstname, and Fisrtname Lastname. Year. Title. Publication City if not major, State 2-letter abbreviation: Publishername.

Periodical Articles

• Scholarly Article
  • Author's full name, inverted so that last name appears first. Year. “Article Title in Title Caps and in Quotes.” Journal Title in Title Caps and Italicized Volume Number(Issue Number):page numbers of article. 
• Newspaper or Magazine Article
  • Lastname, Firstname. Year. "Title," PeriodicalName, Month Day, pp. #-#.

Websites

• WebsitePublisher. YearofPublication. "Title." Retrieved Month(3-letter abbreviation). Day, Year (URL, or D.O.I. if available).

• Page titled: REFERENCES - Use styles; this needs to be Header 1 level
• Double-spaced
• Alphabetical order by first author's last name
• Use authors' first names, not just initials (unless they themselves spell their names using initials, on-purpose)
• Hanging Indent if runs over to another line
• Titles: Title Case (Capitalize all words in title except articles, conjunctions & prepositions unless they start the title or subtitle)
• List all authors; don't use et.al
• If you have multiple references from an author or authors, spell name out on every reference
  • Order these groups of an author's multiple references in chronological order within the over-all alphabetical ordering