Zubrin's books include The Case For Mars, in which he outlines the Mars Direct plan along with speculating on the economic, social and technical viability of future Martian colonization, Entering Space, a more futuristic look at humanity's possible colonization of the solar system and the feasibility of interstellar flight with known physics, and First Landing, a (barely) fictional tale about a near-future Mars flight using the Mars Direct plan.
Zubrin has also released a new fictional work titled The Holy Land. This is a "SF satire on the Middle East crisis and the War on Terrorism and concerns what happens when the liberal Western Galactic Empire relocates the oppressed Minervan sect to their ancient homeland of Kennewick, Washington, in the midst of a USA ruled by Christian fundamentalist fanatics."1