Pagination is a required part of a reference to a book when you only use a specific part of the book for research. It indicates the specific point within a work at which the information to be referenced is located. Pagination is required in periodicals, but if a periodical has no page numbers it may be left out of the citation (this is sometimes the case with articles found on the Internet). You should make a reasonable effort to locate page numbers, they are often present in pdf documents.
Books
If you are citing an entire book pagination is not necessary.
Pagination for part of a book consists of the beginning and concluding pages of the chapter or part.
Place pagination after the title, enclosed in parentheses, and followed by a period. Pagination follows edition and/or volume statements (when these are given). Use the abbreviation p. for one page and pp. for more than one page.
Example:
Margereson, C. (2003). The development of cardiothoracic surgical nursing. Cardiothoracic surgical nursing (pp. 21-55). Blackwell Science.
Journal articles
Pagination consists of the first and last page of the article.
Retain page numbers as they appear in the publication, as XI, v-vii, N37-N49, 230s-252s.
Place pagination information after the volume/issue preceded by a comma.
Example:
Landau, H. (2010, September). Winning grants: A game plan. American Libraries, 41(9), 34-36.
Newspapers
Pagination differs in newspaper articles. Precede the page numbers with p. or pp. as you would with books. Write the page numbers the same as they appear in the newspaper, most newspapers use a number and section letter (i.e. A1; 1H; B5-B7; 1D-2D, 7D).
Example: