https://www.youtube.com/watch?v=pf2L5kr2U5M
https://www.youtube.com/watch?v=flgpRZM1z5Y
https://www.youtube.com/watch?v=QL83BWUN0NQ
https://strathprints.strath.ac.uk/3260/1/strathprints003260.pdf
https://www.ebooks.com/en-tw/95567684/existential-therapies/cooper-mick/?_c=1