List the publisher, store or company of the advertisement first in the citation. This information will provide your readers with the "who" component of the citation. In a traditional reference such as a book or magazine article, this portion is reserved for the author. Because you are dealing with an advertisement, you will list the store or company that is providing the product. Follow the name of the company or store with a period.
Provide the year of the magazine publication second in the citation. This section of the citation tells your reader the "when" of the reference. List the year of the publication followed by a period.
Tell your reading audience the "what" of the citation as the final step. Provide readers with the title of the product or advertisement placed in quotations and followed by a period. Next list the magazine name followed by a comma, the month and day of the volume followed by a comma. Finally, end the citation by listing the page number that the advertisement can be found on. If the advertisement is spread out over multiple pages, list the first page in its entirety and the last two digits of the next pages, separating page numbers with a colon. End the citation with a period. For example; pp. 153:54.