Goralczyk, R (2009). "β-Carotene and Lung Cancer in Smokers: Review of Hypotheses and Status of Research". Nutrition and Cancer. 61 (6): 767–774. doi:10.1080/01635580903285155. PMID20155614.
nih.gov
pubmed.ncbi.nlm.nih.gov
Goralczyk, R (2009). "β-Carotene and Lung Cancer in Smokers: Review of Hypotheses and Status of Research". Nutrition and Cancer. 61 (6): 767–774. doi:10.1080/01635580903285155. PMID20155614.