When the print sources of the historical file were created, book acquisition was not systematic, and references were created only for books sent to APA by their publishers. Nonserials coverage in the historical file is therefore not as comprehensive as it has been since 1987, when PsycINFO began systematic book coverage. These references may be added to the historical file in the future. Differences in the Field Set. Information Book Series Title Book ISBN Book Table of Contents Field Content and Format Characteristics.
Content is variable.
Depending on editorial practices in place when the print reference was created, it may contain all authors, the first four authors followed by et al., or the first author only followed by et al. References from many journals do not include ISSNs unless coverage continued after 1966. Languages other than English are not specified. These terms predate the use of controlled terms from the Thesaurus of Psychological Index Terms .