Here are some mirrors of theory books.

Anarchist Manifesto | K. H. Z. Solneman
P2P Hate Report | Emmi Bevensee
Full Trustnet Thesis | Alexander Cobleigh
Anarchy Works | Peter Gelderloos
A Conquest of Bread | Petr Kropotkin
Trustnet | Alexander Cobleigh
Queering Anarchism | C. B. Daring, J. Rogue, Deric Shannon, and Abbey Volcano
Polyamory and Queer Anarchism | Susan Song
Software and Anarchy | Gnuxie Lulamoon and Hayley Patton