The best bibliogaphic entry would probably be: Smythe, Clark. <em>Unsinkable: Folly on the Titanic</em> Little, Brown: New York, 1976.
That is because it seems to be a book about the Titanic itself, whereas the other ones have to do with:
- topics which are less directly related to the subject-matter (the first entry is about maritime laws and the third one is about the animal and plant populations of the lands near the North Pole),
- personal, relative accounts of the events (like the fourth entry, which is an autobiography of a survivor and therefore describes the wreck through the character's own perspective) as opposed to more factual material.
Absolute monarchy and totalitarian dictatorship are similar because the people have no control over the government. I know this one from honors!