4) Canter PH, Ernst E. Anthocyanosides of Vaccinium myrtillus (bilberry) for night vision - a systematic review of placebo-controlled trials. Surv Ophthalmol. 2004; 49: 38-50.
5) Goodman GE, Schaffer S, Omenn GS, et al. The association between lung and prostate cancer risk, and serum micronutrients: results and lessons learned from beta-carotene and retinol efficacy trial. Cancer Epidemiol Biomarkers Prev. 2003; 12: 518-526.