| Title | Pages | Facts per page | Total Facts |
| Principals of Internal Medicine (Wintrobe) | 2,035 | 100 | 200,000 |
| Textbook of Internal Medicine (Beeson and McDermott) | 1,892 | 100 | 190,000 |
| Disease of the Kidney (Strauss) | 1,456 | 40 | 60,000 |
| The Heart (Hurst) | 1,755 | 50 | 90,000 |
| Clinical Hematology (Wintrobe) | 1,788 | 40 | 70,000 |
Total estimate, allowing for basic science, practical real world experience and other fators: 2 million
Parker, S.G., et al., Towards the simulation of clinical cognition: taking a present illness by computer, in: Readings in Artificial Intelligence, Clancey, W. and Shortliffe, E., eds (Addison-Welsley 1984).