The font used in all the Endless Knot videos is Du Bellay, created by Daniel Midgley. We thank him for making the font available for free.

This is a preliminary list of some of the general bibliographic resources I’ve drawn on or found useful for tracking down etymologies and historical connections:

Linguistic Sources:

The Oxford English Dictionary (OED)
The Dictionary of Old English (DOE)
The Middle English Dictionary (MED)
The American Heritage Dictionary (AHD)
Online Etymology Dictionary (Etymonline)
John Ayto, Dictionary of World Origins
C.T. Onions, The Oxford Dictionary of English Etymology
Ernest Klein, A Comprehensive Etymological Dictionary of the English Language (Elsevier)
Webster’s Dictionary of Word Origins
Robert Hendrickson, Word and Phrase Origins
Wiktionary
Logeion
Indo-European Lexicon
John Ayto, Oxford Dictionary of Slang
Tom Dalzell, The Routledge Dictionary of Modern American Slang and Unconventional English
Mark Forsyth, The Etymologicon
David Crystal, The Story of English in 100 Words
The Editors of the American Heritage Dictionary, Word Histories and Mysteries: From Abracadabra to Zeus
Calvert Watkins, The American Heritage Dictionary of Indo-European Roots
Kenneth Katzner, The Languages of the World
Lewis & Short, A Latin Dictionary (OUP)
Oxford Latin Dictionary (OUP)
Michiel de Vaan, Etymologial Dictionary of Latin and other Italic Languages (Brill)
Robert Beekes, Etymological Dictionary of Greek (Brill)
Guus Kroonen, Etymological Dictionary of Proto-Germanic (Brill)
Vladimir Orel, A Handbook of Germanic Etymology (Brill)
F. Holthausen, Altenglisches Etymologisches Wörterbuch

Other Reference Sources:

Wikipedia
The Encyclopaedia Britannica
Oxford Reference
The Oxford Dictionary of National Biography
Six Degrees of Francis Bacon
Brewer’s Dictionary of Phrase & Fable
New Larousse Encyclopedia of Mythology
M.H Abrams & Geoffrey Galt Harpham, A Glossary of Literary Terms, 10th ed. (Wadsworth, 2012)
William Harmon & Hugh Holman, A Handbook to Literature, 10th ed. (Pearson, 2006)
Michael Lapidge, John Blair, Simon Keynes, and Donald Scragg, The Blackwell Encyclopedia of Anglo-Saxon England (Blackwell, 2001)
Rudolf Simek, Dictionary of Northern Mythology (D.S. Brewer, 1993)
John Lindow, Norse Mythology: A Guide to the Gods, Heroes, Rituals, and Beliefs (OUP 2001)
Andy Orchard, Cassell’s Dictionary of Norse Myth & Legend (Cassell, 1997)
Douglas Gray, The Oxford Companion to Chaucer (OUP, 2003)
Francis Claudon, The Concise Encyclopedia of Romanticism (Omega , 1980)
John A Garraty & Peter Gay, The Columbia History of the World (1972)
Oxford Encyclopedia of World History

The Knowledge Web (website, beta version, with James Burke)

Other Books:

Lawrence S. Cunningham & John J. Reich, Culture & Values: A Survey of the Humanities (Thomson Wadsworth)
Mary Warner Marien & William Fleming, Arts & Ideas (Thomson Wadsworth)
Thomas Cahill, How the Irish Saved Civilization (1995)
Thomas Cahill, The Gift of the Jews (1998)
Thomas Cahill, Desire of the Everlasting Hills (1999)
Thomas Cahill, Sailing the Wine-Dark Sea (2003)
Thomas Cahill, Mysteries of the Middle Ages
Thomas Cahill, Heretics and Heroes (2013)
James Burke, Connections
James Burke, The Day the Universe Changed
James Burke &  Robert Ornstein, The Axemaker’s Gift (1995)
James Burke, The Knowledge Web (1999)
James Burke, Circles (2000)
James Burke, Twin Tracks (2003)
Bill Bryson, A Short History of Nearly Everything (2003)
Justin Pollard, Secret Britain (John Murray, 2009)
Joseph Campbell, The Hero with a Thousand Faces
Robert A. Segal, Myth: A Very Short Introduction (OUP)
Eva M. Thury & Margaret K. Devinney, Introduction to Mythology: Contemporary Approaches to Classical and World Myths (OUP)
Robert Graves, The Greek Myths (Penguin)
David Adams Leeming, The World of Myth: An Anthology (OUP)
H.R. Ellis Davidson, The Rituals of Northern Europe (Penguin)
Kevin Crossley-Holland, The Penguin Book of Norse Myths: Gods of the Vikings (Penguin)
Heather O’Donoghue, English Poetry and Old Norse Myth (OUP, 2014)
Edward Shortland, Maori Religion and Mythology
Ronald Hutton, The Stations of the Sun: A History of the Ritual Year in Britain (Oxford UP, 1996)
Dan Jurafsky, The Language of Food: A Linguist Reads the Menu (2014)
David Wondrich, Imbibe! (Perigee, 2007)
Desmond Morris, Bodytalk: A World Guide to Gestures
Desmond Morris, Gestures
James Bruce Ross & Mary Martin McLaughlin, The Portable Medieval Reader (Viking, 1949)
James Bruce Ross & Mary Martin McLaughlin, The Portable Renaissance Reader (Viking, 1949)
Norman F. Cantor, The Civilization of the Middle Ages (1993)
Malcolm Godden & Michael Lapidge, The Cambridge Companion to Old English Literature (CUP, 1986)