John Keats - Poetry Foundation
https://www.poetryfoundation.org/poets/john-keats
Keats' page on The Poetry Foundation's website, where biographical information, literary essays, and further links to his poems may be found.
The Ballad - Connections
http://www.math.grinnell.edu/~simpsone/Connections/Poetry/Forms/ballad1.html
The article provides an overview of the ballad, outlining its characteristic elements and offering further examples of the genre.
'Proved upon our pulses': Keats in Context - British LIbrary
An article by Andrew Motion published on the British Library's blog that explores the political and philosophical underpinnings of Keats' work.
John Keats - Harry Ransom Digital Collections
https://hrc.contentdm.oclc.org/digital/collection/p15878coll61
A digital collection of Keats' letters and manuscripts.
John Keats Love Letter To Fanny Brawne – 13 October 1819
https://englishhistory.net/keats/letters/love-letter-to-fanny-brawne-13-october-1819/
A letter Keats sent to Fanny Brawne during the same year "La Belle Dame Sans Merci" was composed.