Citations: This book relies on primary source material, with documents extending back to the fourteenth century. Every fact in the book is cited. When a fact has no citation, it is drawn from the immediately preceding citation within the same paragraph. In addition to primary source material, this book also draws upon original translations of non-English sources and scholarly work that synthesized topical areas.
Units of measure: The units reported in this book are the units used in the primary source material.
Spelling: American English spelling is used throughout, except that quotations from historical sources are represented with their original spelling, reflecting in some cases changes to the English language, including word choice, and in other cases British spelling.