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. (1)
Applications for ISSN numbers in the United States:
US ISSN Home Page: http://www.loc.gov/issn/
ISSN Application Form: http://www.loc.gov/issn/form/
Library of Congress
U.S. ISSN Center
101 Independence Ave., S.E.
Washington, DC 20540-4284
Tel.: (202) 707-6452
Fax: (202) 707-6333
Email: issn@loc.gov
Service hours:
Monday-Friday 9:30 am-5:00 pm
References:
1. Wikipedia: https://en.wikipedia.org/wiki/International_Standard_Serial_Number
2. ISSN International Centre or the International Centre for the Registration of Serial Publications (CIEPS): http://www.issn.org/