http://www.conservationinstitute.org/10-most-poisonous-animals-in-the-world/
http://www.planetdeadly.com/human/deadliest-poisons-man
http://www.iflscience.com/health-and-medicine/five-most-poisonous-substances-polonium-mercury/
http://sciencenewstoyou.blogspot.ca/2012/03/top-11-deadliest-things-on-earth.html
http://www.planetdeadly.com/animals/venomous-animals-world
http://www.bbc.com/earth/story/20151022-one-animal-is-more-venomous-than-any-other http://someinterestingfacts.net/top-10-most-deadliest-substance-known-to-man/