摘要：In this paper, two distinguished textbooks of internal medicine, Cecil Textbook of Medicine and Harrison's Principles of Internal Medicine were compared on the basis of citation studies. The latest editions of the textbooks were examined; “ Harrison ” was the 11th ed. (1987), and “ Cecil ” was the 18th ed. (1988). The following results were obtained: 1. Harrison had 280 contributors, and 77 (27.5%) were affiliated with Harvard Medical School. Cecil had 325 contributors, but they were not as concentrated at any one institution as in the case of Harrison . 2. There were 4, 527 citations in Harrison and 4, 040 in Cecil . The proportion of journal citations to total citations was 79.1% in the case of Harrison and 76.2% in the case of Cecil . 3. A list was made of the 20 most frequently cited journals. The most important journal was the N Engl J Med . This journal accounted for 10% of all citations in both textbooks. This list shows that all were U. S. journals with the exception of the Lancet . 4. A list was made of the 10 most frequently cited books. 5. The age of the citations is shown in Fig1. Both graphs indicate that peak age was 2-3 years. Median citation age in Harrison was 4.6 years, and in Cecil it was 4.4 years.
