http://www.travelchannel.com/shows/ghost-adventures/articles/poveglia-islands-haunted-history
http://weekinweird.com/2016/10/25/poveglia-island-is-haunted-by-plague-victims/
https://www.hauntedrooms.com/most-haunted-asylums-hospitals-in-america
https://the-line-up.com/pennhurst-asylum
https://seoultapperilla.com/tag/gonjiam-psychiatric-hospital/
http://www.theparanormalguide.com/blog/gonjiam-psychiatric-hospital
http://www.slate.com/blogs/atlas_obscura/2014/05/30/severalls_hospital_is_an_abandoned_mental_institution_in_essex_england.html
http://eerieplace.com/haunted-severalls-hospital-colchester/
http://theghostdiaries.com/9-haunted-insane-asylums-you-should-never-spend-the-night-in/
http://io9.gizmodo.com/six-abandoned-asylums-with-genuinely-chilling-backstori-512154481
https://en.wikipedia.org/wiki/Essex_County_Hospital_Center
http://www.atlasobscura.com/places/willard-asylum-for-the-chronic-insane
http://www.blumhouse.com/2016/12/20/america-most-haunted-asylum-taunton-hospital-of-massachusetts/
https://exemplore.com/paranormal/Haunted-Insane-Asylums-Some-Of-The-Scariest-Places-On-Earth
http://www.dailypost.co.uk/news/north-wales-news/ghosts-north-wales-hospital-scratch-11251397