https://www.bmj.com/content/327/7429/1459 https://www.bmj.com/content/327/7429/1459 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1584330/ https://www.ncbi.nlm.

https://www.bmj.com/content/327/7429/1459 https://www.bmj.com/content/327/7429/1459 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1584330/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1584330/