One of the lessons I’ve absorbed from the past year is that it’s best to have reference materials in your own home when possible. My Ex Libris #3 – Enciclopedia Dantesca – was the first application of this observation. Now I have two others – Pierre Chantraine’s Dictionnaire Étymologique de la Langue Grecque: Histoire des Mots (in the 2009 reprint) and Alfred Ernout and Antoine Meillet’s Dictionnaire Étymologique de la Langue Latine: Histoire des Mots (in the 2001 reprint). Both are available free on archive.org (Chantraine and Ernout/Meillet) but I find the the friction of use too much to overcome.
Next up is Frisk’s Griechisches Etymologisches Woerterbuch but for now I can continue to use the archive.org version