1. Haag-Streit, A. G. No. 274: The Goldmann slitlamp and applanation tonometer.
2. Haag-Streit, A. G. No. 257: The utilization of the Goldmann applanation tonometer.
3. Goldmann, H.: Applanation tonometer. Conference on Glaucoma (Edited by F. W. Newell). New York, Josiah Macy, Jr., Foundation, 1956, pp. 167–220.
4. Schmidt, T.: Personal communication.