1. [1] Smith T., “Endoscopy. British Medical Association Complete Family Health Encyclopedia”, Dorling Kindersley Ltd., 403-404, (1990).
2. [2] Gärtner A, Belloni P., “Optical designs to improve LED lighting efficiency of medical endoscopes”, LED Professional, https://www.led-professional.com/resources-1/articles/optical-designs-to-improve-led-lighting-efficiency-of-medical-endoscopes, (2020).
3. [3] Brüggemann, D., Blase, B., Bühs, F., Dreyer, R., Kelp, M., Lehr, H., Oginski, S. and Schlegel, S., “Endoscope with distal LED for illumination”, World Congress on Medical Physics and Biomedical Engineering, Springer Berlin Heidelberg, Beijing/China, 2107-2110, (2012).
4. [4] Hensman C., Hanna G.B., Drew T., Moseley H. and Cuschieri A., “Total radiated power, infrared output, and heat generation by cold light sources at the distal end of endoscopes and fiber optic bundle of light cables”, Surgical Endoscopy, 12(4): 335–337, (1998).
5. [5] Todd E.F.D., Ertas H. and Hamel A.J., “Disposable attachable light source unit for an endoscope”, US8029439B2 United States Patent, (2005).