BOWKER SERIALS BIBLIOGRAPHY czyt. 192,318 IRREGULAR Irregular serials and annuals. An international directory.A classified guide to current foreign and domestic serials, excepting periodicals issued more frequently than once a year. 2 ed. New York 1972 R.R.Bowker Company 4° s.XXXV, nlb.1, 2017-3382. Bowker Serials Bibliography.