International Standard Serial Number International Standard Serial Number An International Standard Serial Number (ISSN) is an eight-digit serial number used to uniquely identify a serial publication. The ISSN is especially helpful in distinguishing between serials with the same title. ISSN are used in ordering, cataloging, interlibrary loans, and other practices in connection with serial literature. The ISSN system was first drafted as an International Organization for Standardization (ISO) international standard in 1971 and published as ISO 3297 in 1975. ISO subcommittee TC 46/SC 9 is responsible for maintaining the standard. When a serial with the same content is published in more than one media
What Lies Below be left alone." Supervising producer Jeff Vlaming wrote "What Lies Below", his second episode of the season. Filmmaker Deran Sarafian served as the director, his first and only "Fringe" directional credit. The episode featured one-time guest appearances by actors Demore Barnes, Geoff Pierson, Conrad Coates, Natassia Malthe, and David Richmond-Peck. Actor Joshua Jackson, who plays an infected Peter Bishop in the episode, noted during shooting that he found inspiration from "imagin[ing] the worst hangover I've ever had and multiply it by ten". Actress Jasika Nicole was pleased that the writers decided to let her character discover Walter's secret, commenting "Astrid