https://www.awm.gov.au/visit/exhibitions/anzac-voices/life-trenches
https://onlineexhibits.library.yale.edu/s/wwi-medicine/page/diseases-at-the-battlefield
http://www.vlib.us/wwi/resources/archives/texts/uboatu9.html
https://en.wikipedia.org/wiki/Chemical_weapons_in_World_War_I
https://en.wikipedia.org/wiki/Machine_gun
https://encyclopedia.1914-1918-online.net/article/rifles
https://www.warhistoryonline.com/guns/8-rifles-first-world-war.html
https://www.historyextra.com/period/first-world-war/life-trenches-wwi-guide/
https://en.wikipedia.org/wiki/Eastern_Front_(World_War_I)
http://www.historyisnowmagazine.com/blog/2014/7/29/world-war-one-how-did-the-eastern-front-differ-from-the-western-front
https://en.wikipedia.org/wiki/Russian_entry_into_World_War_I
https://en.wikipedia.org/wiki/Naval_warfare_of_World_War_I
https://en.wikipedia.org/wiki/African_theatre_of_World_War_I
https://en.wikipedia.org/wiki/Trench_foot
https://ergo.slv.vic.gov.au/explore-history/australia-wwi/abroad-wwi/life-trenches