Mapping the core journals of the physical therapy literature.

Objectives: The purpose of this study was to identify (1) core journals in the literature of physical therapy, (2) currency of references cited in that literature, and (3) online databases providing the highest coverage rate of core journals.

Method: Data for each cited reference in each article of four source journals for three years were recorded, including type of literature, year of publication, and journal title. The journal titles were ranked in descending order according to the frequency of citations and divided into three zones using Bradford's Law of Scattering.