Irregular serials & annuals.
Koltay, Emery.
New York : Bowker,
1967-1987.
"A classified guide to current foreign and domestic serials, excepting periodicals issued more frequently than once a year."
"An international directory".
Editor: 1967- E. Koltay.
Also issued on CD-ROM, 1986- , under the title: Ulrich's plus.
Periodicals
Yearbooks
Bowker serials bibliography supplement
Bowker international serials database update
Ulrich's quarterly
Ulrich's plus
Ulrich's international periodicals directory