OBJECTIVE: This study was part of the Medical Library Association's Nursing and Allied Health Resources Section's project to map the nursing literature. It identified core journals in nursing informatics and the journals referenced in them and analyzed coverage of those journals in selected indexes. METHOD: Five core journals were chosen and analyzed for 1996, 1997, and 1998. The references in the core journal articles were examined for type and number of formats cited during the selected time period. Bradford's Law of Scattering divided the journals into frequency zones. RESULTS: The time interval, 1990 to 1998, produced 71% of the references. Internet references could not be tracked by date before 1990. Twelve journals were the most productive, 119 journals were somewhat productive, and 897 journals were the least productive. Journal of the American Medical Informatics Association was the most prolific core journal. The 1998 journal references were compared in CINAHL, PubMed/MEDLINE, Science Citation Index, and OCLC Article First. PubMed/MEDLINE had the highest indexing score.