I don't have any books to recommend, but I can tell you that there are plenty of good companies out there that are full of moral & ethical people. I'm fortunate enough to work for one and I've never seen any corruptness, immorality, or unethical behavior.
I guess what I'm saying is....if you feel like you're in that environment, I'd recommend you change jobs rather than search for how to maintain your standards in that environment.
I don't of any titles, but just try browsing in the Christian section of a bookstore, or even going to a Christian bookstore and going to the business section. I've seen them, but just don't know the titles.
Christians always seem to want to get back into the salt shaker, but that is not where they are called. They are called to be salt and light to a broken and lost world. The worst places is where the Christian needs to be, because those people probably aren’t getting prayed for by anyone, and there is probably no one in their lives to witness to them, and be a light.
I'll willingly go to a troubled area to minister or lead, but I won't devote my life's work to an organization that is corrupt or immoral. That was my point.