https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5442608/
https://www.ncbi.nlm.nih.gov/pubmed/29303952
https://www.ncbi.nlm.nih.gov/pubmed/28154970
http://onlinelibrary.wiley.com/doi/10.1002/ana.25131/epdf
http://journals.sagepub.com/doi/pdf/10.1177/1756285617722347
https://www.ncbi.nlm.nih.gov/pubmed/29406578
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5837230/
http://www.clinph-journal.com/article/S1388-2457(18)30239-6/fulltext
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5809809/#!po=59.0909