Pormann, Peter E. and Smith, E. Savage: Medieval Islamic medicine Georgetown University, Washington DC. Pormann, Peter E.; Savage-Smith, Emilie (2007). Medieval Islamic Medicine. Georgetown University Press. стр. 48. ISBN978-1589011618..
Kienle, Alwin; Lilge, Lothar; Vitkin, I. Alex; Patterson, Michael S.; Wilson, Brian C.; Hibst, Raimund; Steiner, Rudolf (1. 3. 1996). „Why do veins appear blue? A new look at an old question”. Applied Optics. 35 (7): 1151. Bibcode:1996ApOpt..35.1151K. PMID21085227. doi:10.1364/AO.35.001151.CS1 одржавање: Формат датума (веза)
Kienle, Alwin; Lilge, Lothar; Vitkin, I. Alex; Patterson, Michael S.; Wilson, Brian C.; Hibst, Raimund; Steiner, Rudolf (1. 3. 1996). „Why do veins appear blue? A new look at an old question”. Applied Optics. 35 (7): 1151. Bibcode:1996ApOpt..35.1151K. PMID21085227. doi:10.1364/AO.35.001151.CS1 одржавање: Формат датума (веза)
Kienle, Alwin; Lilge, Lothar; Vitkin, I. Alex; Patterson, Michael S.; Wilson, Brian C.; Hibst, Raimund; Steiner, Rudolf (1. 3. 1996). „Why do veins appear blue? A new look at an old question”. Applied Optics. 35 (7): 1151. Bibcode:1996ApOpt..35.1151K. PMID21085227. doi:10.1364/AO.35.001151.CS1 одржавање: Формат датума (веза)