1. Buschmann W. 1972. Ophthalmologische Ultraschalldiagnostik. In: Velhagen K (ed) Der Augenarzt, Vol II. VEB Thieme, Leipzig, pp. 391–464.
2. Coleman DJ, Lizzi FL. 1979. In vivo choroidal thickness measurement. Am J Ophthalmol 88: 369–375.
3. Niesei P. 1962. Messungen von experimentell erzeugten Änderungen der Aderhautdurchblutung bei Kaninchen. Basel, 1962. Quoted in: Duke-Elder (ed) System of Ophthalmology, Vol IV. Kimpton, London (1968).
4. Ossoinig KC. 1979. Standardized Echography: Basic principles, clinical applications, and results. In: International Ophthalmology Clinics, Vol 19, No. 4. Little, Brown & Co, Boston, Massachusetts, p. 144.
5. Riva CE, Grunwald JE, Petrig BL. 1983. Reactivity of the human retinal circulation to darkness: A laser Doppler velocimetry study. Invest Ophthalmol Vis Sci 24: 737–740.