Introduce the exact sentence you wish to quote by using a signal phrase such as "according to" or "in his study of lepers..." Do not let the direct quotation stand on its own; it must be tethered to your words with a signal phrase or text of your own creation.
Identify the author's last name and the year of her publication. For example, the author's surname may be Sheridan, and her book may have been published in 1972.
Add the author's last name and the year of publication to your sentence in this format: According to Sheridan (1972), "lepers form colonies that protect them from further social ostracizing."
Add the quotation's page number in the proper format. Follow the direct quotation with a lower case "p" and a period. Then identify the page number of the source. Put parentheses around the page number reference. End the sentence with a period. An example is:
According to Sheridan (1972), "lepers form colonies that protect them from further social ostracizing" (p. 19).