(1) https://www.ncbi.nlm.nih.gov/pubmed/17726308
(2) https://www.ncbi.nlm.nih.gov/pubmed/25656040
(3) https://www.ncbi.nlm.nih.gov/pubmed/27230230
(4) https://www.ncbi.nlm.nih.gov/pubmed/27288087
(5) https://www.ncbi.nlm.nih.gov/pubmed/23806573
(6) https://www.ncbi.nlm.nih.gov/pubmed/29564656
(7) https://www.ncbi.nlm.nih.gov/pubmed/6943587