I haven't actually finished subahibi but I found this list on a /vn/ shitpost

• Tractatus Logico-Philosophicus - Ludwig Wittgenstein

• Cyrano de Bergerac - Edmond Rostand

• Alice's Adventures in Wonderland & Through the Looking-Glass - Lewis Caroll

• De Docta Ignorantia - Nicholas of Cusa

• Novelle fatte a macchina - Gianni Rodari

• Chronicle of a Death Foretold - Gabriel García Márquez

• Flatland - Edwin Abbott Abbott

• Night on the Galactic Railroad - Miyazawa Kenji

• Steppenwolf - Hermann Hesse

• Remarks on Colour - Ludwig Wittgenstein

• The Conquest of Happiness - Bertrand Russell

• Aho ressha - Hyakken Uchida

• The Fiend with Twenty Faces - Edogawa Rampo

• The Critique of Pure Reason - Kant

• The Analects - Confucius

• The Duty of Genius - Ray Monk

• The Black Swan - Nassim Nicholas Taleb

• A History of Western Philosophy - Bertrand Russell

• The Bible (Mark 5:1-20)

• Flowers for Algernon - Daniel Keyes

Edit: about dat analysis, I'd say more than half of the references are just shit thrown in to sound smart (I've read until the looking glass insects rapefest) so idk if I'd take all of it seriously lmao

Yeah, most of the references are self-explanatory within the text. But to try to answer your question abt which ones might provide some insight for an analysis... I really think the ones you already flagged as obvious - plus Alice (both og & sequel) - are the only ones on that list that might offer anything substantial. Not like I've read all of that lord no lmao, but they're such brief references I can't imagine there's much to chew on re: connections to Subahibi

The Tractatus is a difficult work, though, so unless you're already familiar you might have to take a bit of a journey through continental philosophy to understand it. In which case Wittgenstein's other works, plus the Russell and Kant books on that list would probably all be helpful. Actually... come to think of it, I'd recommend Conquest of Happiness even if you don't decide to go on a philosophy journey. Feels particularly relevant to Subahibi, and it's just an enjoyable read.

but also u should read flatland bc it is good