https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5311041/
https://www.ncbi.nlm.nih.gov/pubmed/28570322
http://www.psychosomaticsjournal.com/article/S0033-3182(17)30054-3/fulltext
http://jnnp.bmj.com/content/early/2017/10/21/jnnp-2017-315720.long
http://journals.sagepub.com/doi/pdf/10.1177/0883073817720340
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5042290/
http://www.pedneur.com/article/S0887-8994(15)30139-9/fulltext
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5089825/
https://www.sciencedirect.com/science/article/pii/B9780444634320000177?via%3Dihub
https://www.ncbi.nlm.nih.gov/pubmed/27590293