Some 420,000 bibliographic data of periodical articles, which were included in Japanese Periodicals Index (Science and Technology) from 1965 to 1971, were retrospectively added to the NDL-OPAC and became searchable via the Internet from February 26, 2007. As of May 31, 2007, the total number of bibliographic data of periodical articles searchable via the NDL-OPAC reached 7,910,026.

Japanese Periodicals Index (Science and Technology) was first issued in 1950 in book form, and was originally named Japanese Periodicals Index (Natural Science). Bibliographic data created in 1975 or later have already been searchable via the NDL-OPAC, but some 1,450,000 bibliographic data (including duplication) created before 1974 were not converted into machine-readable form. In FY2005, some 180,000 bibliographic data created from 1972 to 1974, and in FY2006, some 420,000 bibliographic data created from 1965 to 1971 became searchable via the NDL-OPAC.

We will continue retrospective conversion and maintenance of the data. We hope you will find it helpful.