Jonas, J. B.; Schneider, U.; Naumann, G. O. (1992). "Count and density of human retinal photoreceptors". Graefe's Archive for Clinical and Experimental Ophthalmology = Albrecht von Graefes Archiv Fur Klinische und Experimentelle Ophthalmologie. 230 (6): 505–510. doi:10.1007/BF00181769. ISSN0721-832X. PMID1427131. S2CID206771302.
Jonas, J. B.; Schneider, U.; Naumann, G. O. (1992). "Count and density of human retinal photoreceptors". Graefe's Archive for Clinical and Experimental Ophthalmology = Albrecht von Graefes Archiv Fur Klinische und Experimentelle Ophthalmologie. 230 (6): 505–510. doi:10.1007/BF00181769. ISSN0721-832X. PMID1427131. S2CID206771302.
Jonas, J. B.; Schneider, U.; Naumann, G. O. (1992). "Count and density of human retinal photoreceptors". Graefe's Archive for Clinical and Experimental Ophthalmology = Albrecht von Graefes Archiv Fur Klinische und Experimentelle Ophthalmologie. 230 (6): 505–510. doi:10.1007/BF00181769. ISSN0721-832X. PMID1427131. S2CID206771302.
Jonas, J. B.; Schneider, U.; Naumann, G. O. (1992). "Count and density of human retinal photoreceptors". Graefe's Archive for Clinical and Experimental Ophthalmology = Albrecht von Graefes Archiv Fur Klinische und Experimentelle Ophthalmologie. 230 (6): 505–510. doi:10.1007/BF00181769. ISSN0721-832X. PMID1427131. S2CID206771302.