1. https://www.ncbi.nlm.nih.gov/pubmed/7774387

2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2963395/

3. https://www.ncbi.nlm.nih.gov/pubmed/28096411

4. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6265337/

5.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6265337/figure/Fig2/

6.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5827553/table/T1/?report=objectonly

7. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6265337/

8. https://onlinelibrary.wiley.com/doi/full/10.1111/tme.12405