A writer can emphasize and support his ideas in an essay by citing book passages. Generally, writings submitted for scholastic credit must follow a widely acceptable format. The American Psychological Association and Modern Language Association writing styles are commonly used for high school and college works and have specific rules for quoting book passages.
According to the Publication Manual of the American Psychological Association (Sixth Edition), citations include the authors' last names and publication years at the beginning of book quotes. Page numbers, preceded by the letter p, end quotes. For example, Smith, (2012) states "beta blockers can prevent heart attacks" (p. 246). Book quotes with 40 or more words are indented 1/2 inch from the left margin without quotation marks. The authors' last names with publication dates in parenthesis begin long quotes. The quotes should end with parenthetical page references.
According to the MLA Handbook for Writers of Research Paper (Seventh Edition), citations for short book quotes include the author's last name and page number in parenthesis. For example, "proper use of beta blockers prevents heart attacks" (Smith 244). Long passages of four or more lines are indented 1 inch from the left margin without quotation marks. The parenthetical author's name and page number are placed at the end of the cite.
APA and MLA require full cites in reference or works cited pages of essays. APA cites include the author's name, publication year, book title, and location and name of the publisher. MLA requires the author's last and first name, book title, location and name of the publisher, and year published. MLA also identifies the publication medium at the end of the cite, such as print.