Columbia subject headings:
Computer networks--Directories.
Electronic publishing--Directories.
Information services--Directories.
Harvard subject headings:
BITNET (Computer network)--Directories.
Electronic journals--United States--Bibliography--Periodicals.
Internet addresses--United States--Directories.
Learned institutions and societies--United States--Directories.
Periodicals.
Princeton subject headings:
Computer networks--Directories.
Directories.
Electronic journals--Directories.
Electronic newsletters--Directories.
Electronic publishing--Directories.
Information services--Directories.