Trigonometry by Gelfand & Saul. I mention it here because in school, this was my least favourite part of mathematics, and at least this book seems to show it to advantage:)

Also, Biogeochemical Approaches to Paleodietary Analysis - published in 2002; probably of no immediate usefulness (looking at the table of contents). Also, if you want to base some conclusions on the isotope studies, bear in mind the growing body of evidence that at least C13 and C14's distribution in plants' organs is not really random; who knows how it is for nitrogen, etc.

Also, Misclassification of Smoking Habits and Passive Smoking A Review of the Evidence published in 1988. Description:

How accurate are statements about smoking habits? This book presents the results of a comprehensive review in which the literature on the subject is newly interpreted. It is shown that smokers are misclassified as non-smokers in epidemiological studies often enough to explain the increased lung cancer risk seen in self-reported non-smokers in relation to their spouse's smoking habits. This study overturns the commonly held view that increased risk is a consequence of exposure to environmental tobacco smoke and highlights the difficulty of making valid inferences from epidemiological data. No-one should draw conclusions about passive smoking before reading this book!

BTW, Data Book on Mechanical Properties of Living Cells, Tissues, and Organs looks like a good text for constructing Fermi questions on this kind of stuff.