Is the "Trojan's Horse" Ricken's book?

The Trojan's Horse is Ricken's Severance version of his book. IMO.

Lumon themselves are behind it, so it IS "Trojan's" as in, it is theirs.

They're sending the book into the severed floor in hopes the innies read it, and get brainwashed by it's teachings as it is the teachings Lumon WANTS the innies to know themselves.

So while the innies might read it thinking it's a way out or they'll learn more about the "outside world" they're really learning exactly what Lumon wants them to.