Publications in any medium issued in successive parts bearing numerical or chronological designations and intended to be continued indefinitely. (ALA Glossary of Library and Information Science, 1983, p203)
An optical disk storage system for computers on which data can be read or from which data can be retrieved but not entered or modified. A CD-ROM unit is almost identical to the compact disk playback device for home use.
Communication through a system of conventional vocal symbols.
Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)