Worth noting that bookstores, especially corporate ones do not and usually will outright refuse to stock or even special order any leftist books. They will usually have no ability to even order you something that you're looking for. The furthest left thing you'll see is maybe some Noam Chomsky, angsty radlib YA fiction, or a democrat's ghostwritten memoir.
Yes, you all need to read more theory, but don't forget that we live in a capitalist society that's heavily preoccupied with actively repressing and destroying any leftist thought that may occur in opposition to it.