https://link.springer.com/article/10.1007%2Fs00415-016-8277-y
https://www.ncbi.nlm.nih.gov/pubmed/27639840
https://www.hindawi.com/journals/ad/2016/9450452/
https://www.ncbi.nlm.nih.gov/pubmed/27292273
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4335816/
https://link.springer.com/article/10.1007%2Fs11910-015-0529-1
https://www.ncbi.nlm.nih.gov/pubmed/26202897
https://www.ncbi.nlm.nih.gov/pubmed/26439968
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4506234/