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Zivotofsky AZ, Averbuch-Heller L, Thomas CW, Das VE, Discenna AO, Leigh RJ.Zivotofsky AZ, et al.Vision Res. 1995 Nov;35(21):3029-35. doi: 10.1016/0042-6989(95)00067-a.Vision Res. 1995.PMID: 8533340Free article.